How many months of cash you have left, and what actually changes it. Most calculators give you one number. This one shows you the two levers. Nothing stored.
The cash runway formula
Runway is one division, but the input that matters is net burn, not gross spend:
net burn = money out - money in
runway = cash in bank / net burn
The reason runway is worth calculating rather than eyeballing is that it moves non-linearly. Cutting spend by 10 percent does not add 10 percent to your runway, it adds more, because you are shrinking the denominator. That is why the levers panel above is the useful part: it turns an abstract number into a decision.
The one-sentence definition and the investor benchmarks live in the runway glossary entry. For the reasoning behind the number, read when will you run out of cash, and to separate the two burn figures cleanly, use the burn rate calculator.
How to calculate cash runway
Three numbers, one division. Take the cash you could actually spend today, work out what leaves and what arrives in a typical month, and divide:
cash in bank €180,000
money out / month €52,000
money in / month €28,000
net burn = 52,000 - 28,000 = €24,000
runway = 180,000 / 24,000 = 7.5 months
Two details keep the result honest. Use a three-month average for money in and out, because any single month lies: a quarterly renewal or a late invoice can swing it 30 percent. And strip out one-time items before dividing, since a one-off legal bill inflates burn that will not repeat. The calculator above does the same arithmetic and then shows what cutting spend or growing revenue does to the months.
A calculator answers today; keeping the date current month after month is a different job. If you are choosing how to do that, the cash forecasting software comparison covers eight approaches, from a spreadsheet to accounting-connected tools.