Burn rate and runway calculator
Calculate monthly burn and remaining runway, then see what idle cash would have earned over the same period.
No sign-up · Nothing is collected or sent anywhere · Yield modelled at the 6.00% no-lock tier, as of September 2026
The short version
- Enter cash on hand, monthly revenue and monthly expenses. Everything is computed in your browser: nothing is collected or sent anywhere.
- You get net burn and months of runway — the one number that decides whether the rest of the page concerns you.
- The same period is then replayed with yield: the balance is drawn down month by month while the deployed share earns the 6.00% no-lock tier, as of September 2026.
- Two scenarios are shown: the whole balance deployed, an upper bound no treasurer should actually run, and half of it, closer to a real policy.
- Withdrawals take 48 hours, so only deploy the cash you have already ruled out of the next payroll run. Not a deposit, not FDIC insured, figures gross.
Enter cash, revenue and expenses.
Three monthly figures. Use a trailing three-month average rather than last month alone — one annual invoice can distort a runway by weeks.
Your figures
Everything you can actually draw on. Exclude undrawn credit lines and unsigned commitments.
Cash collected, not revenue booked. Invoices sent in June and paid in September belong to September.
Payroll, contractors, vendors, rent, taxes. This is your gross burn.
What that gives
A straight-line projection with no yield, no new revenue and no new financing. Nothing you type here leaves your browser.
Net burn and months of runway.
Runway is cash on hand divided by net burn. It is the single number that decides whether the rest of this page is relevant to you at all.
Expenses paid minus revenue collected, per month.
Cash on hand divided by net burn, with no yield applied.
The share of gross burn already paid for by collected revenue.
You are cash-flow positive
Revenue collected covers expenses paid, so there is no runway to calculate — the balance grows rather than draws down. In that situation the question is not how long the cash lasts but what it earns while it sits, which is what the idle cash calculator is for.
Net burn, not gross burn
Gross burn is everything you spend. Net burn is what actually leaves the balance once revenue lands. Runway is driven by net burn, but gross burn is what you cut in a downturn — a team reading only the net figure will misjudge how much slack it has.
A runway number is only as good as the month behind it
One heavy month of annual insurance, a tax payment or a hiring wave distorts the figure. Use a trailing three-month average of both revenue and expenses, and rerun the calculator after any change to headcount, since payroll usually moves the number more than anything else.
Yield extends a runway, it does not create one
The extra months below come from interest on a declining balance. On a short runway the effect is small by construction, and the added liquidity constraint can outweigh it. Yield is a return on cash you were going to hold anyway, not a substitute for reducing burn or raising.
What yield would have added.
The balance below is drawn down month by month at your net burn, while the deployed share earns the 6.00% no-lock tier with monthly compounding. Two scenarios: the whole balance deployed, which is an upper bound no treasurer should actually run, and half of it, which is closer to a real policy.
| Scenario | Runway | Interest earned | Runway gained |
|---|---|---|---|
| Cash left idle0% deployed | — | $0 | Baseline |
| Half the balance deployed50% at 6.00% APY | — | — | — |
| Whole balance deployed100% at 6.00% APY — upper bound | — | — | — |
Interest is computed on the declining balance, month by month, at the 6.00% no-lock tier as of September 2026, gross of tax. Deploying half the balance is modelled as an effective 3.00% on the whole balance, which is the same arithmetic. Runway gained is expressed in months at your current net burn — — in the fully deployed case. If revenue already covers expenses there is no runway to extend, and the interest column shows twelve months of interest instead.
What the model assumes
What it does not account for
How to read your runway by stage.
The same runway figure calls for different treasury decisions depending on how deep it is. These bands are conventions used by finance teams, not thresholds we set, and the shorter ones argue against deploying anything.
Fundraising is the only project
At this depth every decision is a financing decision. Do not lock anything, do not commit cash to a 48-hour settlement cycle, and keep the full balance where it clears same day. The yield on six months of remaining cash is rounding error next to the cost of missing payroll.
Deploy nothing you cannot name
A raise takes months, not weeks, and it rarely closes when planned. If any part of the balance is genuinely untouched — a tax provision, a deposit, a milestone payment scheduled for later in the year — that portion can earn. The rest should stay liquid and unencumbered.
A reserve becomes identifiable
This is usually the first point at which segmentation is honest rather than theoretical: operating cash for the next quarter, a buffer for variance, and a reserve you will not touch. The reserve is the only part worth allocating, and the no-lock tier at 6.00% is the tier that matches an uncertain horizon.
Idle cash becomes a real line item
With more than eighteen months of coverage, the reserve is large enough that the rate on it matters to the plan. A term that ends before your next planned raise can be considered, remembering that an early exit returns the capital and forfeits the accrued interest.
Runway sits inside a wider treasury policy — see the treasury management guide for segmentation, the startup treasury page for how this applies after a round, and the rate grid for the tier that matches your horizon.
This calculator is an arithmetic tool, not investment, tax or legal advice. It runs entirely in your browser: no figure you enter is stored, transmitted or associated with you, and no sign-up is required to use it.
Put the reserve to work, keep the runway liquid.
Open an account directly. If your finance team needs the coverage terms and the KYB requirements before that, a call is the faster route.