← all tools
Finance

Runway & Burn

How many months you have. With MRR growth assumptions.

Base — your inputs as-is

Runway
15+ mo
default alive
Gross burn
$120,000
/ month (base)
Net burn (today)
$100,000
/ month
Need to raise
$0
to reach 24mo
Effective spend
$120,000
your inputs
Effective growth
8.0%
/ month

Projected cash balance

next 48 mo
AI explainer

Ask anything about your result

The math above is deterministic. AI explains what it means — it never recalculates the numbers.

About

How many months of cash do you have? Plug in your bank balance, monthly spend, MRR, and growth rate to see when you run out — with revenue growth factored in, not just burn divided by cash.

How it works

  1. 01Enter cash in bank and gross monthly burn.
  2. 02Add current MRR and your expected monthly MRR growth rate.
  3. 03We project cash month-by-month: each month you spend gross burn, earn growing MRR, and net the difference against cash.
  4. 04Runway is the month your balance hits zero — or 'default alive' if MRR overtakes burn first.

Examples

Default alive

$1.5M cash, $120k spend, $20k MRR growing 8%/month. MRR overtakes burn around month 22 and the company never runs out — that's 'default alive'.

Tight 12 months

$1M cash, $150k spend, $10k MRR, 3% growth. You hit zero around month 10. Either raise, cut burn, or accelerate growth — pick fast.

FAQ

What's gross vs net burn?+
Gross burn = total monthly spend. Net burn = gross burn minus revenue. Both matter: net burn drives runway, gross burn drives the size of your next raise.
Should I model collections lag?+
For SaaS with annual prepays, MRR overstates cash inflow. As a hack, use 90% of MRR or model in your spreadsheet. We use MRR as a direct cash proxy here.
What growth rate should I use?+
Use a conservative trailing 3–6 month average. Investors will discount aggressive forecasts; founders should plan for the low case.
Does this model fundraises?+
No — it's a pure cash-out projection. To model a raise, add the raise amount to 'cash in bank' and rerun.

Related tools