Burn Rate & Runway Calculator

Enter your cash balance, monthly expenses, and monthly revenue to find your net burn rate and how many months of runway you have left.

Burn Rate Calculator
Cash Runway
Net Burn Rate / month
Gross Burn Rate / month
Months Until Out of Cash
Cash on Hand
Projected Cash Balance Over Time

How the Burn Rate Calculator Works

Burn rate is how fast a company spends its cash reserves, and runway is how long that cash will last at the current pace. For any pre-profit startup, these two numbers determine how much time you have to reach profitability or raise your next round.

Gross Burn vs Net Burn

Gross burn is your total monthly operating expenses. Net burn subtracts revenue: Net Burn = Monthly Expenses − Monthly Revenue. If you spend $60,000 and bring in $20,000, your net burn is $40,000 a month. Net burn is the figure that actually depletes your bank account.

Calculating Runway

Runway (months) = Cash on Hand ÷ Net Burn. With $500,000 in the bank and a $40,000 net burn, you have 12.5 months of runway. If revenue ever exceeds expenses, net burn goes negative — you are cash-flow positive and runway is effectively unlimited at the current rate.

Tip: Fundraising takes time. A common rule of thumb is to start raising when you have 6–9 months of runway left, so you are negotiating from strength rather than desperation.

Extending Your Runway

You lengthen runway two ways: cut the burn (reduce expenses) or grow revenue. Because runway is cash divided by net burn, even modest revenue gains can add months. Model a few scenarios — a hiring freeze, a price increase, a slower-growth plan — to see how each changes the date your cash runs out. The chart projects your balance forward at the current net burn.

Frequently Asked Questions

How do I calculate burn rate?
Net burn rate equals monthly expenses minus monthly revenue. If you spend $60,000 and earn $20,000 per month, your net burn is $40,000. Gross burn rate is total monthly expenses, ignoring revenue.
What is the difference between gross and net burn?
Gross burn is your total monthly cash spending. Net burn subtracts monthly revenue, showing how much cash you actually lose each month. Net burn is what depletes your reserves and determines runway.
How is cash runway calculated?
Divide cash on hand by net monthly burn. With $500,000 in cash and a $40,000 net burn, runway is 12.5 months. It estimates how long you can operate before needing more cash, assuming spending stays constant.
What is a healthy amount of runway?
Many investors suggest keeping at least 12–18 months of runway, and beginning to raise your next round when 6–9 months remain. More runway gives you time to hit milestones and negotiate financing from a position of strength.
What happens if my revenue exceeds expenses?
Then your net burn is negative, meaning you are cash-flow positive and adding to your reserves rather than depleting them. At that point runway is effectively unlimited at the current rate, though growth spending can change that.

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Written & reviewed by the CalcHeadquarters Editorial Team
Every calculator is built from published formulas and authoritative sources, then independently checked for accuracy before it goes live. Last updated June 2026. Read our editorial policy & methodology.