Ask a founder how many months of cash they have left and watch what happens. The good ones answer in two seconds. The rest open a spreadsheet, squint at it, and say "roughly a year?" That gap is the difference between running your company and hoping at it. A startup runway calculator won't fix your burn rate, but it turns a vague sense of dread into a number you can act on. I tested seven of them so you don't have to.
One thing before the list. Every tool here does the same core math: cash divided by net burn equals months of runway. What separates them is what they do around that math, whether that's modeling your hiring plan, computing your burn multiple, or showing you what a 20% cost cut buys.
What Is a Startup Runway Calculator?
A startup runway calculator is a tool that takes your cash on hand, monthly expenses, and monthly revenue, and tells you how many months you can operate before the bank account hits zero. Most are free, most run in the browser, and the better ones layer on scenario modeling so you can see how changes to spending or revenue move the date.
The core inputs are always the same three numbers. Cash in the bank. Money going out each month. Money coming in each month. If a calculator asks for less than that, it's computing gross runway and quietly ignoring your revenue, which overstates the problem. If it asks for more, the extra inputs usually power scenario features.
How Do You Calculate Runway Without a Tool?
Runway equals cash on hand divided by net burn rate. If you have $500,000 in the bank and you're losing $50,000 a month, you have 10 months. That's the whole formula, and yes, you can do it on a napkin.
The part founders get wrong is the burn number. There are two versions:
- Gross burn is total monthly spend: payroll, rent, software, marketing, everything out the door.
- Net burn is gross burn minus revenue. It's what your bank balance actually loses each month.
Use net burn for runway math. But run the gross burn version too, because it answers a darker question: how long do we last if revenue goes to zero? If those two numbers are far apart and your revenue is concentrated in a customer or two, the gross number is the honest one.
So why use a calculator at all? Because static math assumes nothing changes. Real runway bends with every hire, every churned customer, every month of growth. The tools below handle that part.
Comparison Table: Runway Calculators at a Glance
| Tool | Price | Signup required? | Best for |
|---|---|---|---|
| Founderpath | Free | No | Burn multiple + scenario modeling |
| Warp | Free | No | Modeling hiring plans by role |
| StartuPage | Free | No | Fast gross/net burn breakdown |
| IdeaProof | Free | No | "Default alive" analysis |
| Pilot | Free | No | Simple check from a bookkeeping firm |
| Futureproof | Free | No | Seed and Series A scenario planning |
| Foundra Runway Calculator | Free | No for basics | First-time founders planning the full picture |
Which Startup Runway Calculator Is Best Overall?
Founderpath's burn rate calculator is the strongest all-rounder: free, no signup, and it computes the three numbers investors actually ask about (net burn, cash runway, and burn multiple) in one screen. You enter monthly revenue, expenses, cash on hand, and an expected growth rate, and it charts your cash balance over 24 months.
The scenario comparison is the feature that earns the bookmark. It shows your runway three ways side by side: at current burn, with a 20% cost reduction, and with your revenue growth compounding. Watching a 20% expense cut add months to your life is more persuasive than any budgeting lecture.
It also calculates burn multiple using the Bessemer framework (net burn divided by net new ARR), and grades you against benchmarks: below 1x is excellent, 1x to 2x is good, above 4x is unsustainable. Founderpath is a lender to SaaS companies, so the tool leans SaaS and ends with a pitch for non-dilutive financing. Ignore or explore as needed; the calculator works either way.
Which Calculator Is Best for Modeling Hiring Plans?
Warp's runway calculator is built around the thing that actually drives burn: headcount. Instead of one "monthly expenses" box, it has you add team members by role with annual salaries, plus line items for rent, ad spend, and software. Each expense and each hire can start now or in a future quarter, so you can model "what happens if we bring on two engineers in Q3" without building a spreadsheet.
That start-date feature sounds small. It isn't. Most calculators treat burn as flat, but nobody's burn is flat. Hiring plans are staggered, and a calculator that can't stagger them will miss your real out-of-cash date by months.
Warp is a payroll company, and the tool is lead generation for that, complete with a Windows 95 skin for some reason. The page also publishes burn multiple benchmarks that are worth internalizing: they call 1x to 1.5x the new target for Series A, and cite Midjourney's revenue-per-employee numbers as the efficiency bar AI-era investors now reference. Take the framing with a grain of salt (a payroll company benefits from you thinking hard about payroll), but the calculator itself is one of the best.
What's the Fastest No-Signup Option?
StartuPage and IdeaProof both give you an answer in under a minute with no account. StartuPage's burn rate calculator computes gross and net burn, visualizes where the money goes, and returns runway in months. It's the one to use when you want the number and nothing else.
IdeaProof's runway calculator adds one idea worth the extra 30 seconds: a "default alive" check. Default alive is Paul Graham's question of whether, at current growth and burn, you reach profitability before the money runs out. A runway number alone tells you when you die if nothing changes. Default alive tells you whether anything even needs to change. Two very different emotional states, same three inputs.
What About Pilot and Futureproof?
Pilot's burn rate calculator lives on the blog of their bookkeeping business, and it's the simplest tool on this list: enter your numbers, get burn and runway, read a solid explainer underneath. Pilot does bookkeeping for thousands of startups, so the surrounding guide is grounded in real client data rather than theory. Use it as a sanity check, not a planning tool.
Futureproof's startup runway calculator targets seed and Series A founders specifically. You enter cash, revenue, and expenses, then model different burn scenarios to see how each one moves your out-of-cash date. It sits somewhere between StartuPage's speed and Founderpath's depth. If you're mid-fundraise and want to show a lead investor what the round buys in months, this framing maps neatly onto that conversation.
Where Does Foundra's Runway Calculator Fit?
Full disclosure: I built this one, so weigh my opinion accordingly. The Foundra Startup Runway Calculator is one of the free tools at foundra.ai/tools/, and it does the core job with no signup: enter cash on hand and monthly burn, see exactly when you run out.
The honest comparison: Founderpath gives you deeper scenario modeling, and Warp handles hiring plans better. Where Foundra fits is context. The runway calculator sits next to a break-even calculator, a SaaS revenue calculator, and an equity dilution calculator, all feeding the same planning workflow first-time founders are usually doing when runway comes up. Runway isn't really a standalone number. It's the deadline on everything else in your plan, and it's most useful sitting next to the plan it's constraining.
What Counts as Enough Runway in 2026?
The standard answer is 18 to 24 months after a raise, and it's the standard answer because fundraising itself takes 3 to 6 months. If you start raising with 6 months of cash, you're negotiating with a gun on the table and investors can smell it.
The working thresholds most founders and investors use:
- 18-24 months post-raise: healthy. Enough time to hit milestones for the next round.
- 12 months: the tripwire. Start fundraising, cutting, or accelerating revenue now, not next quarter.
- 6 months or less: critical. Every week matters and your options are narrowing.
But months of runway is only half the 2026 picture. The other half is burn multiple: how much you burn per dollar of new ARR. Capital efficiency expectations have tightened hard since the 2021 era, and both Warp and Founderpath now publish sub-2x as the expectation for companies that want to raise. Twenty-four months of runway with a 5x burn multiple isn't a healthy company. It's a slow-motion problem with good cash reserves.
One more habit worth stealing: recalculate monthly, not quarterly. Burn creeps. Three new software subscriptions, a contractor who became full-time, and an AWS bill that grew 15% will quietly eat two months of runway while you weren't looking.
Key Takeaways
- Runway = cash on hand ÷ net burn. Every tool here is this formula plus features.
- Founderpath is the best overall pick: burn multiple, scenario modeling, and benchmarks with no signup.
- Warp is the one to use when hiring is the question, since it models roles, salaries, and start dates.
- StartuPage and IdeaProof are the fastest checks; IdeaProof adds Paul Graham's "default alive" test.
- Foundra's calculator makes sense when you want runway sitting next to the rest of your planning numbers.
- Target 18-24 months post-raise, treat 12 months as the tripwire, and watch burn multiple as closely as runway.
- Recalculate monthly. Burn creeps faster than founders expect.
FAQ
What is the best free startup runway calculator?
Founderpath's is the strongest overall: no signup, and it computes net burn, runway, and burn multiple with side-by-side scenario comparisons. For modeling a hiring plan, Warp's calculator is better. For a 30-second check, StartuPage or IdeaProof.
How do I calculate my startup's runway?
Divide cash on hand by net burn rate (monthly expenses minus monthly revenue). $400,000 in the bank with $40,000 net monthly burn is 10 months of runway. Run it again with gross burn (ignoring revenue) to see your worst-case number.
What is the difference between gross burn and net burn?
Gross burn is your total monthly spending. Net burn is spending minus revenue, which is what your bank balance actually loses each month. Use net burn for runway math, but know your gross number too: it's your runway if revenue disappears.
What is a burn multiple and why does it matter?
Burn multiple is net burn divided by net new ARR, a capital-efficiency metric popularized by Bessemer Venture Partners. Below 1x is excellent, 1x to 2x is good, above 4x is unsustainable. In 2026, investors weigh it as heavily as runway itself, because it shows what your spending is buying.
How much runway should a startup have?
Aim for 18 to 24 months after a fundraise. At 12 months, start actively fundraising or cutting costs, because closing a round typically takes 3 to 6 months. At 6 months or less, treat it as an emergency.
How often should I recalculate my runway?
Monthly. Burn rates creep as subscriptions, contractors, and infrastructure costs stack up, and revenue rarely lands exactly on plan. A monthly recalculation catches the drift while it's still a small correction instead of a crisis.
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