OnlineTool.me

How Long Will My Money Last Calculator

Model how many years and months your savings may support after monthly spending, income, investment growth, and expense inflation.

Financial Calculators

Estimate How Long Your Money Will Last

Model monthly withdrawals, optional income, investment return, and annual expense inflation.

Your savings duration will appear here
Enter starting savings and monthly spending to calculate automatically.

Planning model only. Returns are treated as smooth monthly growth, while real markets, taxes, fees, emergencies, and spending vary. It is not retirement or investment advice.

What Is How Long Will My Money Last Calculator?

This calculator runs a month-by-month savings projection. It adds the assumed monthly investment return, subtracts spending net of entered income, and gradually changes spending by the annual inflation assumption.

The result answers a planning question, not a guarantee. Real retirement and savings outcomes depend on uneven market returns, taxes, fees, changing income, health costs, emergencies, and withdrawal decisions.

How to Use How Long Will My Money Last Calculator

1

Enter Savings and Monthly Spending

Use liquid or invested savings available for the modeled withdrawals and your expected monthly expenses.

2

Add Recurring Income

Include income that reliably offsets spending during the projection.

3

Set Return and Inflation

Choose assumptions you can explain, including 0% for a simple cash runway.

4

Review and Stress-Test

Read the live duration, then test lower returns, higher inflation, or higher spending.

How the Money Longevity Calculator Works

Annual return and inflation assumptions are converted to equivalent monthly rates. Each month, the model applies the selected cash-flow timing, investment growth, and spending increase.

Projection stops when the balance reaches zero or after 1,200 months. A 100+ year result means the balance stayed positive through that limit.

Monthly return = (1 + annual return)^(1/12) − 1; next balance = current balance × (1 + monthly return) − (spending − income)

Example

With $12,000 savings, $1,000 monthly spending, no income, 0% return, and 0% inflation, end-of-month withdrawals last 12 months.

How Long Will My Money Last Calculator Features

  • Month-by-month balance depletion model
  • Optional recurring income and investment return
  • Annual spending inflation converted to a monthly rate
  • Start- or end-of-month cash-flow timing

Common Use Cases

Build an emergency-fund runway

Set investment return to zero and compare savings with essential monthly spending and temporary income.

Explore retirement withdrawals

Test conservative return, inflation, pension, or Social Security assumptions before seeking personalized advice.

Compare spending reductions

Change monthly spending to see how a lower withdrawal rate may extend the projected duration.

Limits and Important Notes

  • The model assumes a smooth monthly return; real investment returns are volatile and sequence-of-returns risk can materially change outcomes.
  • Taxes, management fees, one-time expenses, income changes, and required distributions are excluded unless reflected in the inputs.
  • Negative net withdrawals can grow the balance, and projections longer than 100 years are shown only as 100+ years.
  • This calculator is educational and is not retirement, investment, tax, or fiduciary advice.

Frequently Asked Questions