Burn Multiple Benchmarks for UK Series A SaaS Startups in 2026

The burn multiple benchmark for Series A has become one of the first numbers a UK investor checks, and in 2026 the bar is higher than it was two years ago. The burn multiple tells you how much cash a startup burns to add each pound of new recurring revenue. It is a blunt, honest measure of capital efficiency, and at Series A it can decide whether a term sheet lands or a process stalls. This guide explains what the burn multiple is, where the 2026 benchmarks sit for Series A SaaS, and what founders can do to move the number in the right direction.

What the burn multiple actually measures

The burn multiple was popularised by David Sacks of Craft Ventures. The formula is simple:

Burn multiple = net cash burned ÷ net new ARR

If your company burns £1.5m over a period and adds £1m of net new annual recurring revenue in the same period, your burn multiple is 1.5x. The lower the number, the more efficiently you are turning investor cash into durable revenue. It uses net new ARR, so churn counts against you: lose customers and the denominator shrinks, which pushes the multiple up and exposes a leaky funnel that vanity growth figures would hide.

Because it captures the whole business in one ratio, spending, growth and retention together, it is harder to game than a headline growth rate. That is exactly why investors like it.

The 2026 burn multiple benchmarks

Sacks set out a broad scale that still frames how the number reads: under 1x is exceptional, 1x to 1.5x is great, 1.5x to 2x is good, 2x to 3x is suspect, and above 3x is a problem. The chart below shows how those bands map onto the language investors actually use.

Chart by Idea London

For Series A SaaS specifically, the benchmark has tightened. In 2023 a 2.0x burn multiple at Series A was widely accepted. Through 2025 and into 2026 the median has moved closer to 1.6x as investors rewarded discipline over growth at any cost. In practice, if you are raising a Series A in London this year, under 1.5x reads as genuinely capital efficient, around 2x is defensible with a strong growth story, and much above that invites hard questions about unit economics.

The important nuance is that the acceptable multiple falls as you scale. A 2.5x burn multiple is forgivable at £500k ARR, where you are still building the machine. The same 2.5x at £5m ARR is a red flag, because by then the model should be proving it can grow without swallowing cash. Judge yourself against companies at your stage, not against a single fixed target.

Why Series A is where the burn multiple bites

At pre-seed and seed, revenue is small and lumpy, so the burn multiple is noisy and investors weight it lightly. Series A is the inflection point. You are raising a larger round on the promise of a repeatable, efficient growth engine, and the burn multiple is the cleanest single test of that promise. A tidy multiple signals that more capital will compound rather than leak. A poor one signals that a bigger cheque simply funds a bigger hole.

UK founders face this against a backdrop of pricier capital and more patient diligence than the 2021 peak. Investors have the time and the comparison data to notice an inefficient business, so the number is worth managing well before you open a round.

It also shapes how much you should raise. A lower burn multiple means each pound of investment stretches further, so a capital-efficient company can often raise a smaller Series A, take less dilution, and still reach the milestones that unlock the next round. A high multiple has the opposite effect: you need more money to hit the same targets, give away more of the company, and carry more pressure to grow into a valuation that may have got ahead of the fundamentals.

How to improve your burn multiple

Because the multiple has a numerator and a denominator, you can work on both. On the revenue side:

Attack churn first. Net new ARR is the denominator, so retention and expansion move the multiple faster than raw new sales. Cutting logo and revenue churn lifts efficiency without spending a penny more.
Sharpen the sales motion. Focus reps on the segments that close and expand, and drop the ones that churn. A shorter payback period feeds straight into a lower multiple.
Raise prices where value supports it. Pricing is often the highest-leverage change a Series A SaaS can make, and it lands entirely in the denominator.

On the burn side:

Match hiring to proven capacity. Front-loaded headcount is the most common cause of a bloated multiple. Hire behind revenue, not ahead of a forecast.
Watch cloud and tooling spend. Infrastructure and per-seat software creep quietly and add to burn with no matching ARR.
Sequence the raise. Deploying a large round the moment it lands can spike burn before revenue catches up. Stage spending against milestones.

Track the multiple every quarter, not just at raise time. A trend that is improving quarter on quarter tells a far better story than a single flattering snapshot, and it is exactly the trajectory a Series A investor wants to see.

Using the benchmark honestly

The burn multiple is a guide, not a verdict. A deep-tech company with long build cycles will read differently from a self-serve product, and a deliberate land-grab in a winner-takes-most market may justify a higher number for a while. What matters is that you know your figure, understand why it is where it is, and can show the path to bringing it down. Sacks’ original essay, The Burn Multiple, remains the clearest primer on the thinking behind it.

Frequently asked questions

What is a good burn multiple at Series A in 2026?

Under 1.5x is genuinely strong and reads as capital efficient. Around 2x is defensible with good growth, and the median for UK Series A SaaS now sits near 1.6x. Above 3x will usually trigger serious questions.

How do you calculate the burn multiple?

Divide net cash burned by net new ARR over the same period. Burning £1.5m to add £1m of net new ARR gives a burn multiple of 1.5x. Using net new ARR means churn works against the number.

Why does the burn multiple matter more than growth rate?

Growth rate alone hides how much cash it costs to achieve. The burn multiple captures spending, growth and retention in one ratio, so it shows whether growth is efficient and sustainable rather than simply bought.

Does the acceptable burn multiple change as we grow?

Yes. A higher multiple is forgivable at low ARR when you are still building. As revenue scales, investors expect the number to fall, so 2.5x at £500k ARR is fine while the same figure at £5m ARR is a warning sign.

What is the fastest way to lower a high burn multiple?

Usually cutting churn and slowing speculative hiring. Retention lifts net new ARR without extra spend, and matching headcount to proven revenue reduces burn, so both sides of the ratio move together.

For more on funding, metrics and building a company in the capital, explore the guides at Idea London.