Calculate your net monthly burn rate and exactly how many months of runway your cash balance gives you.
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| Month | Revenue | Expenses | Net Burn | Ending Balance |
|---|
A burn rate calculator answers the two questions that decide whether a startup survives long enough to succeed: how fast is cash leaving the bank account, and how many months of runway remain before it hits zero. NeftCal's burn rate calculator takes your current cash balance, monthly revenue, and monthly expenses, reports your net monthly burn and gross burn, and then projects the balance forward 24 months while compounding revenue and expense growth — so you see not just today's runway, but the month your cash is projected to run out.
Gross burn is your total monthly spending. Net burn is spending minus revenue — the true cash drain that reduces your balance each month. The simple runway figure divides cash by net burn for a quick snapshot, while the month-by-month projection shows how growth changes the answer: a startup whose revenue is compounding a few percent each month usually outlasts one whose spending is climbing faster than sales. That forward-looking view is what turns a burn rate calculator you check once into a startup cash runway tool you actually manage with.
This tool is useful for startup founders tracking cash between rounds, CFOs and finance leads who need a quick monthly runway check, investors and accelerators reviewing portfolio-company cash positions, and boards preparing for a funding discussion. Anyone who answers to a cash balance — pre-seed, seed, or later stage — can use it to turn rough numbers into a concrete runway figure.
Runway is the central survival metric for a young business. It tells you when you must raise capital, cut costs, or accelerate revenue, and it frames every negotiating conversation with investors. Tracking burn rate month over month also exposes drift early: if net burn keeps climbing while runway keeps shrinking, you have a problem to solve while you still have options. Pairing this calculator with a startup cost calculator — to plan what you need to spend before launch — and a cash flow calculator — to track all money in and out — gives a complete cash picture, not just the burn slice.
Net burn drains your cash balance every month; runway is how long that cash lasts
Gross Burn is total spend. Net Burn subtracts revenue — it's the number that actually determines how fast your bank balance falls.
Growing revenue and rising expenses both compound monthly. A 24-month projection catches trends a single snapshot misses.
Start raising capital or cutting costs when runway drops to 6-9 months — fundraising itself takes months to close.
From cash balance to a 24-month runway projection in under a minute
Enter the total cash your business has in the bank today. This starting balance is what the runway projection draws down month by month.
Input your average monthly revenue and your total monthly expenses. Net burn is expenses minus revenue, so this is where your monthly cash drain is defined.
Enter the expected monthly growth rate for revenue and for expenses as percentages. A negative rate models a revenue decline or planned cost cuts.
The calculator computes net burn, gross burn, simple runway in months, and a full 24-month monthly cash projection.
Check your Net Monthly Burn, Gross Burn, the Runway figure, and the Projected Zero-Cash Month that the projection flags.
Use the monthly projection table and the cash balance chart to see exactly when the balance crosses zero and how your growth assumptions change the trajectory.
A realistic startup burn rate and runway calculation, step by step
Suppose a SaaS startup has $300,000 in the bank. It earns $20,000 per month in revenue and spends $45,000 per month in operating expenses. Revenue is growing about 5% per month and expenses about 2% per month. These are the calculator's default values, so you can press Calculate and follow along.
Explanation: The simple runway of 12.0 months assumes a constant $25,000 net burn. The projection shows the true picture is slightly better — but not by much. Because revenue grows faster (5%) than expenses (2%), the monthly net burn shrinks from $25,000 toward roughly $21,100 by month 13. That slower drain stretches the balance to $14,798 by the end of month 12, but it is still not enough to avoid hitting zero: month 13's net burn of about $21,154 takes the balance to roughly −$6,355. The calculator therefore reports a Projected Zero-Cash Month of 13 — about a month later than the simple 12.0-month figure, and a clear signal to start fundraising now.
Sanity check: month over month, the projection table confirms net burn falls steadily — $25,000 → $24,900 → $24,768 — while the balance stays positive through month 12. If this startup cut expenses to $40,000 instead, month-1 net burn would drop to $20,000 and simple runway would rise to 15 months, which is exactly the kind of what-if you can test instantly in the calculator.
What your runway and burn figures actually tell you
Your runway — how many months your current cash lasts at your current burn — is the single most important number for judging how much time you have to reach your next milestone. These bands are general reference points used widely in the startup community, not a formal industry standard, and the right target depends on your stage, your sector, and how quickly you can raise.
| Runway | General Read | Typical Context |
|---|---|---|
| Under 6 months | Urgent — act immediately | Raise capital or cut costs now; few options if cash hits zero |
| 6 – 12 months | Standard for seed-stage | Begin fundraising now; room to course-correct but limited |
| 12 – 18 months | Healthy | Comfortable buffer; the range most investors want to see |
| Over 18 months | Strong | Ample time to hit milestones; room to invest in growth |
For net burn: a stable or falling net burn means your cost discipline is holding and revenue is filling the gap. A rising net burn, even with growing revenue, is worth investigating — it usually means spending is growing faster than sales.
For gross burn: gross burn is your cost-control signal. Compare it month over month regardless of revenue; a growing gross burn with flat revenue is the classic warning sign that runway is about to shrink quickly.
For the projected zero-cash month: treat it as a planning deadline, not a prediction. The projection assumes steady compounding growth and no one-time events, so any material change to cash, revenue, or costs should trigger a re-run.
Risk considerations: the model ignores one-time costs, funding rounds, seasonality, and tax obligations, and it trusts the growth rates you enter. If revenue growth is optimistic, real runway will be shorter than projected — stress-test with a lower growth rate before making decisions.
This calculator provides estimates for educational and informational purposes only. Results may vary depending on business conditions, accounting methods, taxes, market trends, and other factors. It should not be considered financial, legal, tax, accounting, or investment advice. Consult qualified professionals before making business decisions.
Where a cash runway calculator earns its keep
Set a raise size and timeline based on the runway you need to reach your next milestone.
Track net burn monthly so cash levels never become a surprise board-room reveal.
Report runway and burn trends to investors and LPs with one clear number.
Model how a new salary changes net burn and shortens runway before you hire.
See exactly how much runway each expense reduction buys back.
Give the board a month-by-month cash projection instead of a single ratio.
Test slower revenue growth or faster spending to see the downside case.
Keep a small operation alive by budgeting runway without outside capital.
Combine burn with SaaS metrics to judge whether growth justifies the spend.
Determine how much bridging cash you need to reach profitability.
Plan a launch campaign budget against the runway it consumes.
Prepare for a revenue dip by modeling a negative revenue growth rate.
What this burn rate calculator does well, and where it can't replace a full cash-flow forecast
Three numbers describe your cash position — make sure you're comparing the right ones
| Measure | What It Tells You | How This Calculator Computes It | Where It Matters Most |
|---|---|---|---|
| Gross Burn | Total monthly spending, before any revenue | Monthly Expenses | Cost discipline and efficiency review |
| Net Burn | The actual monthly cash drain on your balance | Monthly Expenses − Monthly Revenue | Runway math and fundraising needs |
| Runway | How many months your current cash lasts | Cash Balance ÷ Net Burn, plus a 24-month projection | Survival planning and fundraising timing |
Burn rate focuses on the operating gap that drives runway. For a broader view of every dollar moving in and out — including financing and investing activity — use the Cash Flow Calculator, which compares total inflows against outflows.
Common questions about burn rate and runway
Official guidance to complement this calculator — not a substitute for professional financial advice
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