Cash Runway Calculator

Estimate runway from cash balance, revenue, gross margin, and operating expenses (optionally with revenue growth).

Runway answers a simple question: how many months can you operate before cash hits zero at your current net burn-

This calculator estimates net burn from revenue, gross margin, and operating expenses, and optionally simulates runway with a monthly revenue growth assumption.

Prefer an explanation- Read the guide.
 
$
If collections lag, adjust this closer to cash collected per month.
$
 
%
 
$
 
%
 
Used to estimate required revenue for the target runway.
Tip: you can type commas (e.g., 10,000).

Example

Using the default inputs, the result is:
5 months
Cash balance
$500,000
Monthly revenue (cash-in proxy)
$150,000
Gross margin
80%
Monthly operating expenses (cash out)
$220,000
Monthly revenue growth (optional)
0%
Months to simulate
24
Target runway (months) (optional)
0

How to calculate

  1. Enter your current cash balance.
  2. Enter monthly revenue and gross margin (to estimate gross profit).
  3. Enter monthly operating expenses (cash basis).
  4. Optionally add a monthly revenue growth rate to model improving burn.

Formula

Net burn = operating expenses - (revenue * gross margin); Runway = cash balance / net burn (if net burn > 0)
  • Monthly revenue is used as a proxy for cash inflow (collections timing can differ).
  • Gross margin is treated as a simple % of revenue for gross profit.
  • Operating expenses are treated as cash outflows and constant in the simulation.

FAQ

Why is runway different from profitability-
Runway is about cash. You can be profitable on an accounting basis but still have cash issues due to collections timing, prepayments, capex, or working capital changes.
Should I include non-recurring revenue-
If it reliably produces cash inflows (services, one-time fees), you can include it, but label it clearly. For SaaS planning, recurring revenue is often the most stable input.

Common mistakes

  • Using booked revenue instead of collected cash (AR timing matters).
  • Using accounting expenses when cash outflows differ (capex, prepaids, deferred revenue).
  • Assuming growth without accounting for growth costs (sales/marketing, infra).

Quick checks

  • Use consistent time units (monthly vs annual) when entering rates and cash flows.
  • Run a sensitivity check on the input that drives the result most (often discount rate or growth).
  • Treat the output as a decision aid, not a prediction; validate assumptions with reality.