Series B Funding Amounts (And Why the $27M Average Is Misleading)

What the Number You Keep Seeing Is Missing

Type "series b funding amount" into Google and you will find the same figure recycled across dozens of pages: $27 million. Some sources say $25 million. Others say $30 million. They are all technically correct and practically useless.

The $27 million average comes from aggregating all Series B rounds across all sectors, all geographies, and all market conditions. It tells you what a Series B looked like on average across a period that included a market correction, a funding drought, and a historic AI boom all at once.

That number cannot tell you what a Series B looks like today. Nor can it tell you what investors expect from your company, or how much you should be raising.

This article breaks down what is happening at Series B right now, using data from Carta State of Private Markets reports, PitchBook-NVCA Venture Monitor data, announced deal flow, and sector-level breakdowns that most coverage skips entirely.

The picture is more complicated than one number. If you are preparing to raise, go in knowing what the numbers mean for your sector and stage.

What the Aggregated Data Shows

Start with the macro. Total startup funding on the Carta platform in came in at nearly $120 billion, up close to 17% from the prior year. Q4 alone delivered $36.1 billion - the most lucrative fundraising quarter since the post-pandemic bull market peak.

That sounds like a hot market. But here is the catch most headlines miss.

Total deal count in fell to a six-year low. Fewer rounds are happening. The ones that are happening are larger. Capital is concentrating into a smaller number of bigger bets, and almost all of those big bets are in AI.

Across all stages and all industries, the average round size in Q4 climbed to $30.2 million, up from $19.3 million in the same period a year earlier. That is a 57% increase in average check size in one year, while the number of deals fell.

This is what Carta describes as a bifurcated market. A lot of companies are raising ordinary rounds. A smaller group of companies - almost entirely AI-focused - are raising rounds that skew every average dramatically upward.

What does this mean in practice? The $27 million average gets pulled up by mega-rounds that have nothing to do with where the median company lands. And the median gets pulled down by the large volume of smaller non-AI deals that still make up most of the deal count.

Neither number gives you the full picture. You need sector context.

The Bifurcated Reality at Series B

When you examine publicly announced rounds across sectors, the spread of real Series B deals looks like this.

From an analysis of 50 unique Series B rounds announced in the current funding environment, the median round came in at $90 million. The average was $159 million. The 25th percentile sat at $38 million. The 75th percentile was $200 million.

That is a staggeringly wide range. And the distribution is not a bell curve. It is heavily skewed by sector.

More than one in four announced Series B rounds now exceeds $200 million. That was almost unheard of five years ago outside of late-stage outliers. Today it is a standard bucket.

It is worth noting that publicly announced rounds skew larger than the full universe. Smaller rounds attract less press. So the $25M-$50M bucket is almost certainly underrepresented in public announcements relative to its true share of total deal count.

But for anyone benchmarking against publicly visible deals - which is what most founders and investors do - the picture is shifting upward.

The AI Premium at Series B Is Massive

The single biggest driver of Series B amount inflation is sector. Specifically, whether a company has an AI-forward story or not.

When breaking down Series B deals by category, AI and robotics deals had a median round size of $100 million. Non-AI deals had a median of $40 million. That is a 150% premium for AI positioning at the same funding stage.

This tracks with Carta full-market data. At Series A, the median AI startup valuation is 38% higher than the median non-AI valuation. At Series E and beyond, the AI valuation premium reaches 193%. It widens at every stage.

The AI concentration at the largest rounds is striking. At Series D, 58% of all cash raised across the entire market went to AI startups. And median valuations were up at every stage, including a staggering increase in the upper tiers where AI dominates.

This has an important practical implication for founders. If you are in AI, robotics, defense tech, or any sector with an AI infrastructure angle, your comp set is not the $27 million average. Your comp set is the $100 million median for AI-specific deals - and possibly higher if your category is hot.

If you are in a sector without a convincing AI angle - say, traditional consumer goods or offline services - then $25 million to $50 million is likely the realistic range, and the bar for closing at the higher end of that range is demanding.

Some Deals to Make This Concrete

Nothing grounds a benchmark like seeing where real companies came out.

Physical Intelligence, an AI robotics software company, raised $600 million in its Series B. The round was led by Alphabet CapitalG, and the company reached a post-money valuation of $5.6 billion. The business had no commercial revenue at the time of the raise - it was funded entirely on the strength of the founding team, research pedigree, and the size of the robotics AI opportunity. That is a ceiling case. It shows what AI positioning, top-tier backers, and a massive market can do to a Series B amount.

Bedrock Robotics raised $270 million at Series B. Positron AI came in at $230 million. OpenLedger's crypto-adjacent Series B closed at $500 million. These are not statistical outliers anymore. They are a growing share of the announced deal universe.

At the other end of the spectrum, a SaaS company at $10 million ARR with 80% year-over-year growth and solid unit economics is more likely to close a Series B in the $30 million to $60 million range, depending on sector, growth rate, and investor appetite for the category.

The point is not that every company should aim for $600 million. The point is that quoting a single average number as the Series B benchmark is almost meaningless when the range runs from $15 million to $600 million depending on who you are.

Median Pre-Money Valuation at Series B

Round size is only half the picture. Valuation matters just as much, because it determines how much dilution you take for a given check size.

According to Carta data, the median pre-money Series B valuation for primary rounds was $118.9 million. For bridge rounds, the median pre-money valuation was $142.4 million. Both numbers represented significant year-over-year increases - up from $102.8 million and $80.8 million respectively in the prior year period.

For context, PitchBook data for SaaS specifically showed a median pre-money Series B valuation of $168.2 million - a figure that reflects how the software sector, particularly AI-adjacent software, is commanding a premium over the broader market average.

What does this mean in dilution terms? If a company raises $30 million on a $120 million pre-money valuation, it is giving up 20% of the company. If it raises $30 million on a $170 million pre-money valuation, it is giving up about 15%.

One of the most founder-friendly trends of the current market plays directly into this.

Dilution Is at a Record Low at Series B

Median dilution at Series B has fallen to 12.9%, according to Carta full-year data. That is down from roughly 15% a year prior, and it is a record low.

Across all rounds from seed through Series C, median dilution fell from about 18% to 16% over the same period. Two years earlier it stood at 19%. The trend is consistent and founder-friendly.

What is driving this? Higher valuations, primarily. When your pre-money valuation rises faster than the check size, dilution falls. For founders at strong companies - especially those with AI positioning and solid metrics - founders are giving up less equity per dollar raised than they were three years ago. You are giving up less of your company per dollar raised than founders did three years ago.

This does not mean every founder has this leverage. It means the best-positioned companies are seeing it. If your metrics are below the threshold investors are looking for, the old dilution norms apply or worse.

What Investors Need to See to Write a Series B Check

The amount you raise and the valuation you achieve depend almost entirely on whether you clear the minimum thresholds investors set before they will even engage seriously.

The ARR floor has moved up over the past several years. Before the funding peak, $2 million to $4 million in ARR was enough to have a Series B conversation in many sectors. That floor has risen. From what I see in the market, growth-stage investors look for $5 million to $20 million in ARR as the entry range for a Series B, with $8 million to $12 million being a reasonable target for SaaS companies.

Growth rate matters as much as absolute ARR. A company at $5 million ARR growing at 150% is more interesting to Series B investors than a company at $8 million ARR growing at 40% year-over-year. The trajectory, not the snapshot, is what determines whether a company looks like a Series B candidate or a company that needs another year.

Here is a practical threshold summary for non-AI SaaS at Series B:

• ARR: $8M - $20M
• Year-over-year growth: 100% or above is strong; 50-80% is workable if retention is exceptional
• Net Revenue Retention (NRR): 100% minimum; 115-125% is solid; 125%+ is excellent
• Burn multiple: Below 2x is the threshold most investors enforce; below 1x is elite
• CAC payback: Under 12 months
• LTV to CAC ratio: Above 3x at minimum; above 4.5x is what top-tier investors want
• Rule of 40 score: Above 40%, with 50%+ for premium valuations

For AI-first companies, some of these metrics are interpreted differently. Investors will accept negative or pre-revenue status if the technical pedigree and market size justify it. But that is for the exceptional case, not the standard one.

One thing that is consistent across sectors: the burn multiple threshold has tightened dramatically. In the prior bull market, investors tolerated burn multiples of 3x to 4x. Today, the ceiling is closer to 2x, and many growth investors pass without a meeting if that number is higher.

The Timeline From Series A to Series B Has Lengthened

One of the most important and least-discussed data points around Series B is how long companies are waiting between rounds.

The median company that raised a Series B in early had waited 2.8 years since its Series A. Carta flagged this as the longest median interval on record. The market has re-calibrated expectations.

Companies are staying on Series A capital longer. They are getting more out of it. And founders are arriving at Series B with better metrics than they would have if they had rushed to raise 18 months in. And the compressed deal count - fewer total rounds happening per quarter - means each company that does close is better qualified.

From Series B to Series C, the average gap is around 28 months. This is the cadence founders should be planning around when they model out how much runway they need from their Series B raise.

The rule of thumb most experienced investors use: raise enough to get to Series C milestones with 12 to 18 months of runway to spare at the end. You do not want to be raising your next round from a position of desperation. Negotiating strength comes from not needing the money immediately.

Fewer Deals, Bigger Checks - The Structural Shift

Venture capital is consolidating: fewer deals, larger checks, tighter filters. Total round count in fell to a six-year low. But total dollars deployed rose. This means the market is becoming more concentrated and more demanding in its selection criteria.

Down rounds are becoming less common. Fewer than 14% of new fundings in Q4 were down rounds - the lowest rate in three years. That is good news for founders who have grown into their valuations. But it is also a signal that the market is getting cleaner. Companies that cannot justify an up-round are simply not raising. Some are running lean, others have extended runway, and some are quietly winding down.

This is different from the correction years where down rounds were common and companies raised on any terms to survive. The current market is one where strong companies raise on exceptional terms and weak companies struggle to find a term sheet at all.

What Happens Right After a Series B Closes

One tactical angle that almost every explainer article misses: the 60 to 90 days immediately following a Series B close are the period of highest commercial opportunity for B2B vendors targeting these companies.

Companies that have just closed a round have budget, board pressure to show progress, and a mandate to scale. They need sales infrastructure, marketing tools, legal support, compliance tooling, data providers, and recruitment services - all at once. Decision cycles are shorter. Budget approvals are faster. The intent signal is as clear as it gets.

This is why B2B operators who track funding announcements as a lead trigger consistently outperform those who do not. The funded company is not just a potential customer. It is a company that has been explicitly given money to buy the things you sell.

The signal degrades fast. By the time a company is six months post-close, the initial budget allocation is done and the new priorities are set. Move within days or miss it.

Tracking Series B announcements as a prospecting trigger - and reaching out within days, not weeks - is one of the higher-ROI changes a B2B sales team can make. Try ScraperCity free to search and filter recently funded companies by industry, location, and company size, so you can build a real-time list of newly funded companies to contact rather than relying on discovery by chance.

How Sectors Stack Up at Series B

Sector is the biggest variable in the Series B equation. Here is how different categories currently compare.

AI and Machine Learning: Median Series B around $100 million. Valuations elevated across the board. Investors will accept pre-revenue for companies with strong research pedigree.

SaaS (non-AI): Median pre-money valuation around $118 million. Round size typically $25 million to $50 million. Investors expect $8 million to $15 million ARR and 80% or better growth. Rule of 40 above 40%.

Robotics and Physical AI: Among the most active categories for large rounds. Physical Intelligence at $600 million and Bedrock Robotics at $270 million define the high end. Typical range is $50 million to $300 million for companies with strong technical differentiation.

Defense and Dual-Use Tech: One of the fastest-growing Series B categories by announcement volume and audience interest. Defense tech Series B announcements generate more social engagement than any other sector - roughly 5.8 times the average engagement of an AI announcement, based on analysis of public tweets around funding announcements. This reflects growing mainstream interest in the category.

Fintech: More normalized ranges of $30 million to $80 million. Investors expect clear unit economics and regulatory clarity. Revenue requirements are firm.

Biotech and Health: Wide variance based on therapeutic category and clinical stage. Capital-intensive by nature. Series B rounds that are pre-clinical look very different from post-Phase II raises.

The Metrics That Kill Series B Rounds Before They Start

I see it repeatedly - founders arriving at Series B with specific, identifiable metric gaps that experienced investors catch in the first 30 minutes of due diligence.

The most common killers are worth naming directly.

NRR below 100% after $5 million ARR. If existing customers are shrinking their contracts faster than new customers are growing them, the revenue engine has a leak. Every investor models this, and the math gets ugly fast.

Burn multiple above 2x. Spending $2 or more to generate $1 of new ARR is a flag in the current market. The ceiling has tightened from 3-4x in the prior bull run to a strict 2x today. Below 1.5x is where premium valuations start.

Cap table problems from early convertible notes. If the seed stage was funded with multiple messy convertible instruments that have not been cleaned up, it creates complications in due diligence. Experienced growth investors see this immediately and it slows or kills processes.

Series A investors not participating. When your existing investors are not writing a check in your Series B, new investors notice. If you cannot explain clearly why, it becomes a conversation about what your insiders know that new investors do not. You need a proactive and credible narrative here, not silence.

A financial model you cannot walk through in real time. At Series B, investors expect the founder or CFO to have the model at their fingertips. Being able to walk through revenue drivers, cohort assumptions, and unit economics live - without fumbling - signals operational maturity. Fumbling through it signals you are not running the business on the numbers.

How to Set Your Series B Target Amount

Given the wide range of actual Series B amounts, how do you figure out what to raise?

Work backward from what you need to achieve to make a Series C inevitable.

First: define your Series C milestone. What ARR, what market position, what product state would make a Series C a straightforward raise? That is your target destination.

Second: calculate how much it costs to get there. Model out headcount, sales and marketing investment, infrastructure costs, and product development needs with conservative growth assumptions.

Third: add runway buffer. I've seen founders consistently land their next fundraise with 12 to 18 months of runway remaining. So if your model says you will hit Series C milestones in 24 months, you need 36 to 42 months of runway from your Series B close.

Fourth: sanity-check against market data. If your calculation comes out to $90 million but you are a $5 million ARR non-AI SaaS company, the math is disconnected from reality. Cap it at what the market will support for your profile. If your calculation comes out to $20 million but you are an AI robotics company with strong momentum, you may be leaving money on the table.

One practitioner framework that gets used by operators who have successfully closed growth rounds: raise whatever you need to hit the next milestone, with a buffer for when things do not go to plan - but do not raise twice that amount. Oversized rounds come with oversized dilution and investor expectations that can become a trap. Raising to next milestone plus a reasonable buffer is the discipline that serves founders best across the long run.

Valuation Multiples That Drive the Numbers

Behind every Series B round size is an implicit revenue multiple negotiation. Understanding how these multiples work helps you anchor your ask.

For SaaS companies, the multiple is typically applied to ARR. In the peak of the prior bull market, post-money valuations of 20x ARR were common at Series B. In the correction, that compressed to 8x to 12x. The market recovered, AI re-inflated valuations, and strong companies are now seeing 12x to 20x ARR, with AI-first companies at 20x to 40x or more.

For a company at $10 million ARR growing at 120% year-over-year with strong retention, a 15x to 18x multiple is defensible in the current environment. That implies a pre-money valuation of $150 million to $180 million. If you raise $30 million on $160 million pre-money, you are diluting by about 16%. That aligns with the Carta record-low dilution figure of 12.9% at Series B, suggesting the best companies are seeing even better terms than that.

The multiple you achieve depends on your growth rate, retention, sector, and the competitive dynamics in your fundraising process. Running a process with multiple interested parties - rather than a single-VC conversation - almost always results in better valuation outcomes.

The Disappearing Sub-$5 Million Round and What It Means for Series B

One structural trend in the broader market has downstream implications for Series B expectations. Sub-$5 million early rounds are disappearing. PitchBook tracked the numbers: small rounds have nearly vanished, even at the seed stage.

What is happening instead: the rounds that do happen are larger. Seed rounds are getting bigger. Series A checks are getting bigger. By the time a company reaches Series B, the capital base that preceded it is larger, the expectations are higher, and the valuation foundation is more expensive.

This matters for Series B math because higher seed and Series A valuations create a higher floor for Series B pre-money. A company that raised $3 million at a $15 million post-money seed, then $12 million at a $50 million post-money Series A, needs a Series B pre-money of at least $100 million to represent an up-round. That sets a floor, not a ceiling - but it also sets a standard that incoming investors expect you to clear with metrics.

The compressing of deals at every stage into fewer, bigger rounds is creating a market where each funding event carries more weight. A failed Series B process is harder to recover from than it was five years ago, because the field of alternative sources has thinned.

How to Find and Approach Series B Stage Investors

How much to raise is one question. Who to target is the harder one. Series B investors are a distinct category from seed or Series A investors.

They are typically growth-stage VC firms rather than early-stage generalists. They want to see repeatable go-to-market, not just a promising product. They model exits with specific assumptions about IPO timelines and acquisition multiples. Their checks are larger and their holding periods are different.

The investors who led Series A rounds can be a starting point, but the process usually involves finding new lead investors. In the rounds I've seen up close, a new external lead comes in and existing investors fill out the round behind them.

I've watched founders build their Series B target lists by looking at who has backed similar companies at the Series B stage in the last 18 to 36 months. This is mapping by sector, check size range, and stage preference. A firm that primarily writes $50 million to $150 million Series B checks in enterprise software is a different conversation than a firm that writes $15 million Series B checks in consumer health.

One pattern from operators who have closed multiple growth rounds: start the relationship-building process 12 to 18 months before you intend to raise. Send brief quarterly updates. Get on radars. By the time you are ready to launch a formal process, the conversation should be a continuation of an existing relationship, not a cold introduction.

Another approach that experienced operators use: track who announces investments in your sector and reach out to the investor directly - not through a warm intro but with a specific, informed message about why your company is relevant to their portfolio thesis. This works better than most founders expect, especially at the growth stage where investors are looking for companies that fit a known pattern.

What Happens After Series B

Closing a Series B is a milestone, not a destination. The companies that use it well versus the ones that waste it make very different decisions in the first 90 days after close.

The capital should go toward one of three things: expanding go-to-market reach, building the product infrastructure that supports the next order of magnitude of customers, or entering new markets with a validated playbook. What it should not go toward is hiring that does not map to revenue drivers, or operational overhead that does not scale.

The failure rate for companies after Series B drops dramatically compared to earlier stages. A company that has cleared the Series B bar has demonstrated enough of the fundamentals that catastrophic failure becomes less common. Stagnation is the problem. A company that raises a strong Series B and then misses its growth targets for two consecutive years loses momentum, market position, and the ability to raise a clean Series C.

The 28-month average from Series B to Series C is tight. That is roughly two to two and a half years to build a business that can make a compelling case for the next major raise. Most of that case is built in the first 18 months after the Series B close.

The 90-day post-close window matters for more than just the company itself. Vendors, partners, and service providers who reach newly funded companies in that window find decision-making is faster and budgets are more accessible than at any other point in the company lifecycle.

The Bottom Line on Series B Funding Amount

Stop anchoring on $27 million. That number was never a prediction for any individual company. It was an average across thousands of companies in wildly different sectors, markets, and time periods.

The actual distribution of Series B amounts today looks like this:

• Non-AI, traditional SaaS: $25M to $60M is the realistic range
• AI-first SaaS or infrastructure: $50M to $150M is the range for strong companies
• Robotics, physical AI, defense tech: $100M to $600M+ for top-tier companies
• Median pre-money valuation across all Series B: $118.9M for primary rounds
• Median dilution at Series B: 12.9% - a record low
• Time since Series A for the median company raising Series B: 2.8 years

The market is generous to the best companies right now. Valuations are up, dilution has hit record lows, and capital is available. But the deals are concentrated. Fewer companies are raising. The ones that do raise are the ones that cleared the bar on ARR, growth rate, retention, and burn.

If you are preparing a Series B, the question is not what the average company raised. The question is what your metrics justify and what the market will pay for a company with your profile. Those are two different numbers. Whether they converge or diverge determines whether your round is competitive or a grind.

Run the math on your sector, your ARR, and your growth rate. Check the comps on what has closed in your category in the last 12 months. And start the investor relationship process earlier than feels necessary. Series B processes that close at premium valuations almost always have 12 to 18 months of pre-work behind them.