Boneyard Tools

Burn Rate Calculator

Measure how fast your startup spends cash. Enter your starting and ending cash over a period to get the net monthly burn, add revenue for the gross burn, and see the runway left from your ending balance.

How to use the burn rate calculator

  1. Enter your cash at the start and end of the period.
  2. Enter the number of months the period covers.
  3. Add monthly revenue to also see gross burn, then read the runway.

Examples

500,000 down to 350,000 over 3 months

start 500000, end 350000, 3 months
Net burn 50,000/mo, 7 months of runway

Same period with 20,000 monthly revenue

start 500000, end 350000, 3 months, revenue 20000
Gross burn 70,000/mo

Frequently asked questions

What is burn rate?

Burn rate is how much cash a company spends each month. Net burn is the cash lost per month after revenue, while gross burn is the total cash spent before counting revenue.

How do you calculate burn rate?

Net burn per month equals the starting cash minus the ending cash, divided by the number of months in the period. If you know monthly revenue, gross burn equals net burn plus that revenue.

What is the difference between gross and net burn?

Gross burn is everything you spend in a month. Net burn subtracts revenue from that spend, so it reflects how fast your cash balance is actually shrinking. Investors usually focus on net burn.

How is runway worked out here?

Runway is your ending cash divided by the net monthly burn, giving the months of cash left at that pace. If net burn is zero or negative, your cash is not shrinking, so the runway is effectively infinite.

What if my cash went up over the period?

Then net burn is negative, which means you generated cash rather than spending it. The calculator shows a negative net burn and treats the runway as infinite.

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