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How-to guide

How to Calculate How Long Will My Money Last: Formula, Steps & Examples

Learn how to calculate How Long Will My Money Last — the formula explained step by step, with worked examples and a free calculator to check your answer.

By Aarav Mehta, CFA, MBA Finance · Updated Jun 2026 · 2 min read

Calculating your money lasts (months) is straightforward once you know the How Long Will My Money Last formula and what each input means. This guide explains the method in plain language, walks through a manual calculation, and gives worked examples you can follow — then you can do it instantly with the How Long Will My Money Last Calculator.

What is How Long Will My Money Last?

The How Long Will My Money Last calculation tells you your money lasts (months) from a few simple inputs. The figure you are solving for here is the money lasts (months).

The How Long Will My Money Last formula

This calculation combines several inputs through a multi-step method rather than a single one-line formula. Enter the values below and the calculator resolves each step in order. The inputs it needs are:

  • Current savings — a money amount. Example: ₹10,00,000.
  • Monthly withdrawal — a money amount. Example: ₹10,000.
  • Annual return on savings — a percentage, such as an annual rate. Example: 6%.

How to calculate it step by step

  • Write down the current savings (for example, ₹10,00,000).
  • Write down the monthly withdrawal (for example, ₹10,000).
  • Write down the annual return on savings (for example, 6%).
  • Apply the formula above to get your money lasts (months).
  • Double-check the result with the How Long Will My Money Last Calculator.

Worked examples

Example 1

Input / OutputValue
Current savings₹10,00,000
Monthly withdrawal₹10,000
Annual return on savings6%
Money lasts (months)139
Money lasts (years)11.6

With current savings of ₹10,00,000, monthly withdrawal of ₹10,000 and annual return on savings of 6%, the money lasts (months) works out to 139.

Example 3

With current savings of ₹5,00,000, monthly withdrawal of ₹10,000 and annual return on savings of 6%, the money lasts (months) works out to 58.

ResultValue
Money lasts (months)58
Money lasts (years)4.8

Tips for an accurate result

  • Keep your units consistent — mixing, say, months with years or grams with kilograms is the most common source of error.
  • Round only at the very end. Rounding inputs early can shift the final answer noticeably.
  • Re-run the numbers whenever an input changes, rather than estimating from an old result.
  • Annual rates must be converted to the period you are calculating for (for example, divide an annual rate by 12 for a monthly figure).

Prefer not to do the maths by hand? — the How Long Will My Money Last Calculator does it instantly, for free, with the formula and a worked example built in.

Continue exploring finance calculators with these tools: SIP Calculator, EMI Calculator, CAGR Calculator, FD Calculator, Effective Annual Rate (EAR) Calculator.

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Frequently asked questions

Gather each input, apply the formula step by step keeping your units consistent, and round only at the end. You can verify your answer instantly with the How Long Will My Money Last Calculator.

It uses the standard formula with exact arithmetic, so the result is correct for the inputs you enter. Bear in mind that real-world outcomes can still differ when underlying assumptions change.

Aarav Mehta · CFA, MBA Finance

Aarav reviews every finance formula on CalcHub for accuracy.