Free Tool
Startup Runway Calculator
Use our free startup runway calculator to find out exactly how many months of cash your business has left — and when you will reach breakeven. Enter your cash balance, monthly burn, and revenue for an instant result — no sign-up required.
How to Use This Startup Runway Calculator
- Current Cash Balance: Enter the total cash your business holds right now — across all bank accounts.
- Monthly Expenses: Enter your total monthly outgoings — salaries, rent, software, marketing, and any other fixed or variable costs.
- Monthly Revenue: Enter your average monthly revenue from sales or services. If pre-revenue, enter 0.
- Expected Funding (optional): Enter any one-time cash injection you expect to receive — from investors, grants, or loans. This is added to your cash balance.
- Monthly Revenue Growth % (optional): Enter an expected monthly revenue growth rate. The calculator will project when your revenue will cover your expenses (breakeven) and show this on the chart.
- Click Calculate Runway to see your net burn rate, runway in months, projected cash-out date, and breakeven point.
Startup Runway & Burn Rate Calculator
Full Breakdown
Cash Balance Over Time
How to Interpret Your Runway
Under 6 Months — Danger Zone
Act immediately. You are at high risk of running out of cash. Cut non-essential costs, accelerate revenue, and start fundraising conversations now — raising capital takes longer than most founders expect.
12–18 Months — Healthy
A stable position. Most investors like to see 12–18 months of runway post-funding. You have enough time to execute your plan and hit milestones before needing to raise again.
Default Alive — Excellent
Revenue ≥ expenses. You are “Default Alive” — profitable or on a clear path to profitability before cash runs out. You can survive indefinitely without additional funding.
What is Startup Runway?
Startup runway is the number of months your business can continue operating before it runs out of cash, assuming its current burn rate remains constant. It is one of the most important metrics any founder should know — alongside monthly burn rate, revenue growth, and gross margin.
Runway is calculated by dividing your total available cash by your net burn rate. Net burn rate is simply your monthly expenses minus your monthly revenue — the net amount of cash your balance reduces by each month. If your revenue equals or exceeds expenses, your net burn is zero or negative, meaning you are cash-flow positive and have infinite runway.
Real-World Example — SaaS Startup
A SaaS startup has just closed a seed round and wants to understand its financial position:
Cash Balance: £150,000
Monthly Expenses: £18,000 (salaries, tools, cloud hosting)
Monthly Revenue: £3,000 (SaaS subscriptions)
Net Burn Rate: £18,000 − £3,000 = £15,000/month
Runway: £150,000 ÷ £15,000 = 10 months
Now suppose the founders add a 5% monthly revenue growth rate. By month 4, monthly revenue has grown to ~£3,646. By month 13, revenue exceeds £18,000 — the business reaches breakeven. The runway chart shows this visually: cash declines slowly, then stabilises as revenue growth closes the gap.
Without the growth projection, the founders might panic about their 10-month runway. With it, they can see a credible path to Default Alive — a very different strategic position.
The Formulas
Total Cash =
Cash Balance + Expected Funding
Net Burn Rate =
Monthly Expenses − Monthly Revenue
Runway (months) =
Total Cash ÷ Net Burn Rate
Key Terms Explained
Gross Burn Rate
Total monthly cash expenditure before any revenue. The raw amount leaving the business each month.
Net Burn Rate
Monthly expenses minus monthly revenue. The actual rate at which your cash balance falls each month.
Breakeven
The month when monthly revenue equals monthly expenses. Net burn reaches zero and the business stops consuming cash.
Default Alive / Default Dead
Default Alive = current trajectory reaches profitability before cash runs out. Default Dead = will run out before breakeven without new funding.
How to Extend Your Startup Runway
There are two levers: reduce burn (cut costs) or increase revenue. Here are practical actions under each:
Reduce Monthly Burn
- → Audit all SaaS subscriptions and cancel unused tools
- → Delay non-essential hires
- → Renegotiate supplier and contractor rates
- → Switch to remote or co-working to reduce rent
- → Pause paid marketing channels with poor ROI
- → Explore government grants or R&D tax credits
Increase Monthly Revenue
- → Focus sales effort on your highest-value customer segments
- → Introduce annual pricing to pull forward cash
- → Add a higher-priced tier to existing product
- → Reach out to churned customers with re-engagement offers
- → Pursue strategic partnerships or channel deals
- → Launch a productised service to generate near-term cash
When Should You Start Fundraising?
Raising investment takes significantly longer than most founders expect. The timeline from first investor conversation to cash in the bank is typically 3–6 months for a seed round — and longer for later stages. Here is a practical rule of thumb:
18 months
Start fundraising
Begin conversations when you have 18 months of runway left
12 months
Actively fundraising
Be in active investor meetings with term sheets in sight
6 months
Close the round
Target cash in bank with at least 6 months to spare
Starting too late puts you in a weak negotiating position. Investors can tell when a founder is desperate — and will price accordingly.
Frequently Asked Questions
What is a startup runway calculator?
A startup runway calculator tells you how many months your business can survive at its current burn rate before running out of cash. You enter your cash balance, monthly expenses, monthly revenue, any expected funding, and an optional revenue growth rate. The calculator works out your net burn rate, runway in months, projected cash-out date, and breakeven point.
What is startup runway?
Startup runway is the number of months a business can continue operating before its cash reaches zero, based on its current net burn rate. It is calculated as Total Cash ÷ Net Burn Rate, where Net Burn Rate = Monthly Expenses − Monthly Revenue. For example, £150,000 cash, £20,000 expenses, and £5,000 revenue gives a net burn of £15,000 and a runway of 10 months.
What is a good startup runway?
Most investors recommend at least 12–18 months of runway. Under 6 months is a danger zone — you should be cutting costs or fundraising immediately. More than 24 months is generally very safe. After a funding round, the goal is to use the runway to reach the next meaningful milestone that supports the next fundraise.
What is the difference between gross burn rate and net burn rate?
Gross burn rate is your total monthly cash expenditure before any revenue. Net burn rate is gross burn minus monthly revenue — the actual rate at which your cash balance falls each month. Net burn is the more important figure for calculating runway because it reflects real cash depletion after accounting for what the business earns.
What does Default Alive mean for a startup?
Default Alive is a term from Y Combinator. A startup is Default Alive if its current revenue growth trajectory will take it to profitability before cash runs out — without needing more funding. Default Dead means it will run out before breakeven unless it raises more money. Knowing which category you are in is one of the most important things a founder can understand about their business.
Related Free Calculators
Use these alongside runway to get a complete financial picture of your startup.
Need a full financial model?
Go deeper with a premium template
Our Cash Flow Forecast template lets you model burn, revenue growth, and investor funding scenarios across a full financial year in Excel or Google Sheets — from £9.99.