Business & SaaS

Burn Rate & Runway

Calculate how long your startup's cash will last at current spending.

Burn rate is the rate at which a company spends down its cash reserves. Runway is how many months of operation remain. Every founder needs to know these numbers at all times.

Enter your numbers

Current Cash Balance ($)

Monthly Revenue ($)

Monthly Expenses ($)

Results update as you change the inputs. Calculations run in your browser.

Runway

14.3 months

net Burn: -$35,000/mo
gross Burn: $55,000/mo
warning Zone: Adequate runway

See the formula

Formula and method

Runway = Cash Balance / (Monthly Expenses - Monthly Revenue)

Gross burn is total monthly cash out. Net burn is the cash difference after revenue. Runway is cash balance divided by net burn. Standard startup benchmark is 12-18 months of runway.

Worked examples

Early stage SaaS

Current Cash Balance ($):: 800000
Monthly Revenue ($):: 15000
Monthly Expenses ($):: 70000

Runway: 14.5 months

Pre-revenue startup

Current Cash Balance ($):: 350000
Monthly Revenue ($):: 0
Monthly Expenses ($):: 45000

Runway: 7.8 months

Assumptions and limits

Revenue and expenses constant throughout runway
No additional funding or revenue growth modeled

This tool provides an educational estimate. Rules, rates and personal circumstances can change the answer. Review the assumptions before relying on a result. Report a correction.

Common mistakes to avoid

Confusing gross burn with net burn — net burn is what actually depletes your bank account.
Not accounting for one-time large expenses (legal, equipment, events) in the monthly average.
Planning to exactly zero — never let runway fall below 3-6 months before raising or cutting.

Frequently asked questions

How much runway should I have before fundraising?

Ideally start a fundraising process when you have 6-9 months of runway remaining. Fundraising typically takes 3-6 months, and you want to negotiate from a position of strength, not desperation.

What is a good burn multiple?

Burn multiple = Net Burn / Net New ARR. A ratio under 1.5x is considered efficient. Above 2x is burning too much per dollar of growth. The metric was popularized by Bessemer Venture Partners.