Smart Business Math

Burn Rate Calculator

Measure how quickly cash leaves the business each month after revenue.

Calculator

Use 0 if pre-revenue.

Results

Net burn rate

$17,000.00

Cash leaving each month

Gross burn (expenses)

$25,000.00

What this means

Net burn of this size means cash is shrinking each month. Pair this with runway so you know how long you can operate at this pace.

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Burn Rate Summary

Net burn rate = Monthly expenses − Monthly revenue. Positive net burn means you are drawing down cash; zero or negative means you are covering costs.

Explanation

Net burn is the monthly cash shortfall (or surplus if negative).

Gross burn is total monthly spending before subtracting revenue.

Business implication: growth spending only works if runway and milestones still line up—know the burn first.

Step-by-step example

Expenses $25,000/mo, revenue $8,000/mo:

  1. Net burn: $25,000 − $8,000 = $17,000/mo
  2. Gross burn: $25,000/mo

Formula

Gross burn = Monthly expenses

Net burn = Monthly expenses − Monthly revenue

Helpful tips

  • Separate one-time spends from recurring burn so planning stays honest.
  • Pair with Runway Calculator every time cash or spend changes.

FAQ

What is burn rate?

Burn rate is how fast a business spends cash. Gross burn is monthly expenses; net burn is expenses minus revenue—the cash gap you must fund from savings or fundraising.

Which number should I use for runway?

Use net burn when you have revenue. If pre-revenue, net burn equals gross burn. Feed that into the Runway Calculator.

Is negative burn bad?

Negative net burn means surplus (revenue exceeds expenses). That is generally healthy—just still watch receivables and one-time costs.

How accurate is this calculator?

It uses average monthly figures you provide. Seasonal businesses should use a representative month or a rolling average.

Related tools

Key terms

Burn rate

Definition. How fast a business spends cash—usually net monthly cash decrease when expenses exceed cash in.

In simple terms. Startups and early freelancers use burn to understand how aggressive spending is relative to cash on hand. Positive cash generation is the opposite of burn.

Burn rate ≈ monthly cash out − monthly cash in (when out > in)

Example. Spend $12,000 and collect $7,000 in a month → about $5,000 monthly burn.

Common mistake. Calling all expenses “burn” even when revenue covers them, or ignoring one-time cash events.

Related calculators. Burn Rate Calculator, Runway Calculator

Related terms. Runway, Cash flow

Runway

Definition. How many months current cash can fund the business at the current burn rate.

In simple terms. Runway is a planning clock—not a prediction of success. It tells you how long you have to grow revenue, cut costs, or raise funds before cash hits zero.

Runway (months) ≈ cash balance ÷ monthly burn rate

Example. $60,000 cash and $10,000/month burn → about 6 months of runway.

Common mistake. Using an optimistic burn that ignores upcoming known costs, or forgetting taxes and owner draws.

Related calculators. Runway Calculator, Burn Rate Calculator

Related terms. Burn rate, Cash flow

Cash flow

Definition. The movement of cash in and out of the business over a period—not the same as profit on paper.

In simple terms. You can be profitable and still short on cash if customers pay late or you buy inventory up front. Cash-flow views focus on timing.

Net cash flow = cash in − cash out (for the period)

Example. Invoicing $20,000 but collecting $8,000 while paying $12,000 in bills creates a cash squeeze despite strong sales.

Common mistake. Equating booked revenue with cash in the bank.

Related calculators. Cash Flow Forecast Calculator, Accounts Receivable Days Calculator

Related terms. Accounts receivable days, Burn rate, Runway

See all terms in the Glossary →

Notes & Assumptions

Burn rate is a standard startup and SMB cash-management metric, especially for venture-backed and bootstrapped teams.

Last reviewed: July 2026