How the runway calculator works
Enter your savings, monthly take-home pay and monthly spending, then describe the change: a raise or pay cut as a percentage, a number of months with no income, a new monthly bill, or a one-off cost. The calculator projects your savings month by month for two years, both with and without the change.
Your runway is how long your savings last. The calculator shows when savings would run out, the lowest point they reach, and how long they would last if all income stopped today.
Using it to plan ahead
Try the presets to test common situations before they happen. If a job loss would run your savings out before income is likely to return, that tells you how big an emergency fund you need, or which spending you would cut first.
- A positive monthly surplus means savings grow; a negative one means they shrink every month.
- Months without income are modelled from next month, with income returning afterwards.
- A one-off cost is taken from savings straight away.
Frequently asked questions
How long will my savings last if I lose my job?
Divide your savings by your monthly spending for a rough answer. For a fuller picture, enter your numbers above with the number of months you expect to be without income; the calculator shows when your savings would run out and how low they would go.
How big should my emergency fund be?
A common guideline is three to six months of essential expenses, and more if your income is irregular or would be hard to replace. Use the job loss setting to see what that means for your own spending.
How does a pay cut affect my budget?
A pay cut reduces your monthly surplus by the same amount. If your surplus turns negative, your savings start shrinking every month. Enter the cut as a negative percentage to see the effect.
Can I afford a new monthly bill like a car payment?
Add it as a new monthly bill. If your monthly surplus stays positive and your savings still cover several months of expenses, it is more likely to be manageable.