Burn Rate Calculator
Calculate startup gross and net monthly burn from cash balance or monthly P&L.
Written by Golam Rabbani, Founder & Lead Engineer
How to use this burn rate calculator
- Choose a mode: "From cash balance" (uses two balances over a period) or "From P&L" (uses monthly expenses and revenue).
- In cash mode, enter starting cash, ending cash, months in the period, and average monthly revenue (optional).
- In P&L mode, enter monthly operating expenses and monthly revenue (optional).
- Press Calculate to see gross and net monthly burn.
- Pair the result with the Runway Calculator to see how many months of cash remain.
About this burn rate calculator
The burn rate calculator gives a founder or operator the two numbers every board deck asks for: gross burn (total monthly cash going out) and net burn (gross burn minus revenue coming in). Investors usually focus on net burn because it controls runway, but operators also need gross burn to spot expense bloat masked by a few large customer payments.
Worked example (cash mode): the company started the quarter with $500,000 in the bank and ended with $380,000, over 3 months, with average monthly revenue of $10,000. Net burn = ($500,000 − $380,000) ÷ 3 = $40,000/month. Gross burn = $40,000 + $10,000 = $50,000/month — meaning total monthly expenses are about $50k and revenue offsets a fifth of that.
Use the cash-balance mode for a retrospective look at a closed period, and the P&L mode for forward-looking planning when you have a budgeted monthly expense and revenue line. Everything runs locally in your browser.
FAQ
- What is the difference between gross and net burn?
- Gross burn is total cash spent per month — payroll, rent, cloud, marketing, the lot. Net burn subtracts cash revenue from gross burn. If you spend $80k/month and bring in $30k/month, gross burn is $80k and net burn is $50k.
- When should I use cash-balance mode vs. P&L mode?
- Cash-balance mode looks at real money in the bank over a period and is the most honest measure for closed quarters. P&L mode uses accrual numbers and is better for forecasting next month or modelling a budget change.
- What if revenue exceeds expenses?
- In P&L mode, net burn is floored at zero — you are not burning, you are profitable. In cash mode, the calculator flags the case (ending cash > starting cash) so you can re-check the inputs.
- Does burn rate include one-off items?
- Cash-balance mode automatically reflects everything that hit the account (including one-offs). P&L mode reflects whatever you put in the expense line. For trend analysis it is common to strip one-offs and report "underlying" burn separately.
- Is the calculator free and private?
- Yes. It is free and runs entirely in your browser. No financial data leaves the page.