Business Startup Tools2 min check

Startup Cash Runway

A quick founder check: how many months of operations your current cash supports at today's burn rate.

Short answer

Cash runway = cash in bank ÷ net monthly burn (spend minus revenue). Healthy runway is 18+ months; under 9 months means start fundraising now; under 3 months is critical. The biggest mistake founders make is treating gross spend as burn — only the net figure (after revenue) matters.

Step 1 of 10%

How it works

The calculator subtracts monthly revenue from monthly spend to get net burn, then divides cash by burn for runway in months. It also flags when you should be raising (typically 9–12 months out).

Worked example

£120k cash, £18k spend, £6k revenue → £12k net burn → 10 months runway. Begin fundraising conversations now; close round inside 6 months.

Who should use this

•Pre-seed and seed founders
•Bootstrapped businesses tracking sustainability
•Operators preparing board updates

Common mistakes

×Counting committed-but-uncollected revenue
×Forgetting VAT and PAYE bills due quarterly
×Not modelling 13-week rolling cash separately from monthly view

Frequently asked questions

When should I raise?▾

Start when runway is 9–12 months; rounds typically take 4–6 months to close.

Should I cut staff?▾

Cut early and once. Multiple small cuts kill morale and rarely save the company.

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Startup Costs Estimator →Business Plan Checklist →VAT Registration Checker →