Plainhub
Free tool

Burn rate calculator

Enter what you have in the bank and what moved last month. You get gross burn, net burn and how many months of runway are left. No signup, nothing stored.

Net burn
€24,000
per month
Gross burn
€52,000
total money out
Runway
7.5
months of cash left

The burn rate formula

Two formulas cover everything. Gross burn is what you spend. Net burn is what you actually lose once revenue is counted:

gross burn = money out in the month
net burn   = money out - money in
runway     = cash in bank / net burn

Net burn is the number that decides how long you have. €180,000 in the bank with €52,000 going out and €28,000 coming in is €24,000 of net burn, which is 7.5 months of runway. If revenue covers your costs, net burn is zero and runway stops being the constraint.

One caveat that catches founders out: a one-time cost inflates the month it lands in. A €10,000 legal bill is real cash, but it will not repeat, so strip it out before projecting forward or your runway will look shorter than it is. For the longer version, read What is burn rate? and the two formulas you need.

Common questions

What is the burn rate formula?

There are two. Gross burn is all the money leaving your account in a month. Net burn is gross burn minus the revenue coming in, so net burn = money out - money in. Net burn is the one that decides your runway.

How do I calculate burn rate?

Take one month. Add up everything that left the bank: payroll, tools, rent, ads, contractors. That is gross burn. Subtract the revenue that came in over the same month and you have net burn. Divide your cash balance by net burn to get runway in months.

What is the difference between gross burn and net burn?

Gross burn only looks at spending, so it shows the true size of your cost base. Net burn nets off revenue, so it shows how fast your bank balance is actually shrinking. A company with high gross burn can still have low net burn if revenue covers most of the costs.

What is a good burn rate for a startup?

There is no universal number, because it depends on your cash and your stage. The useful test is runway, not burn: most investors want to see at least 12 to 18 months after a raise, and under 6 months is where cost or fundraising decisions stop being optional.

Should one-time costs count in burn rate?

Include them in gross burn for the month they hit, since the cash really did leave. But when you use burn to project runway, strip out one-off items like a legal bill or a hardware purchase, or you will forecast a burn that repeats when it will not.

Stop recalculating this every month

This tool gives you one snapshot. Plainhub keeps it live: you type what happened, like “Paid €4,000 for Meta ads”, and your burn and runway update as you go. No bank logins, no spreadsheet.

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