How long will my savings last?
Type your savings and what you spend in a month. You get the months — rounded down, the way Pennyjar rounds its runway — and the calendar month the money runs out. No interest, no inflation.
Your savings and your spending
The calculator needs JavaScript on this page. How it counts is explained below.
Savings: money you could reach within a few days. Money still coming in: a part-time wage, a pension payment, rent from a room — anything that arrives every month. The numbers in the boxes are an example: replace them with yours.
How the number is worked out
- Months = savings ÷ what you spend in a month. If money keeps coming in, only the part of your spending that it does not cover is taken from savings: savings ÷ (spending − money coming in). If it covers all of your spending, nothing is taken and the savings do not run out in this calculation.
- Rounded down. One decimal below ten months, whole months from ten up — the rule Pennyjar uses for its runway — so a result never claims a month that is not covered yet. A runway of 0.99 reads 0.9. For example, savings of $3,400 against $3,890 a month is a runway of 0.8 months, and $18,000 against $4,200 is 4.2.
- The month it runs out is counted on the calendar from today: whole months first, then the rest as a share of the month it lands in. Only the month and the year are shown, and they come from the rounded-down number on screen, so the two always agree.
- Money coming in is a feature of this page. The runway in Pennyjar is savings ÷ spending and does not subtract income.
What this calculation leaves out
No interest on the savings, no investment returns, no inflation, no taxes, and no change in spending or in the money coming in. It is not a retirement calculator: it counts no Social Security, pension or investment income unless you type it as a fixed monthly amount in the last box, and a result of many years is arithmetic, not a forecast.
How long will my savings last at different amounts?
Find your savings on the left and your monthly spending along the top. Every cell is savings ÷ spending, rounded down the same way.
| Savings | $2,000 | $3,000 | $4,000 | $5,000 | $6,000 | $8,000 |
|---|---|---|---|---|---|---|
| $5,000 | 2.5 | 1.6 | 1.2 | 1 | 0.8 | 0.6 |
| $10,000 | 5 | 3.3 | 2.5 | 2 | 1.6 | 1.2 |
| $15,000 | 7.5 | 5 | 3.7 | 3 | 2.5 | 1.8 |
| $20,000 | 10 | 6.6 | 5 | 4 | 3.3 | 2.5 |
| $25,000 | 12 | 8.3 | 6.2 | 5 | 4.1 | 3.1 |
| $30,000 | 15 | 10 | 7.5 | 6 | 5 | 3.7 |
| $40,000 | 20 | 13 | 10 | 8 | 6.6 | 5 |
| $50,000 | 25 | 16 | 12 | 10 | 8.3 | 6.2 |
| $75,000 | 37 | 25 | 18 | 15 | 12 | 9.3 |
| $100,000 | 50 | 33 | 25 | 20 | 16 | 12 |
The same number in Pennyjar
Pennyjar is an iPhone and iPad app with three tabs: Goals, Challenges and Cushion. On the Cushion tab it shows this number as how many months of spending your savings would last: under a month, short of your target, or covered. Under it, the app names one next step.
Coming soon to the App Store
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A calculation from your numbers and the rules on this page. It is not financial advice, and it says nothing about investing.
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Last reviewed 8 October 2026