When to use this calculator
Project retirement savings, inflation-adjusted spending needs and a modelled funding gap. Deterministic scenario, not a forecast or safe-withdrawal recommendation. Uses the same constant return before and after retirement; spending and pension grow with inflation. Excludes fees, taxes, market sequence risk and spending after the planning end age. Contributions stay fixed in nominal terms.
Explore the retirement planning calculators for other questions in this topic. For a related calculation, use the Annuity Due Future Value Calculator: Estimate future value of equal beginning-of-month deposits.
Use today’s money only in the fields labelled that way
Retirement spending and pension income are entered in today’s purchasing power, then increased with the inflation assumption. Contributions before retirement remain fixed nominal amounts. The output fund is expressed in money at retirement, so compare it with the required fund shown on the same basis.
PUTTING IT INTO PRACTICE
Retirement: a worked example
The values below are an illustrative example, not a recommendation. Replace them with measurements or assumptions that match your question.
| Input | Example value |
|---|---|
| Current age (integer) | 40 |
| Retirement age (integer) | 60 |
| Planning end age (integer) | 80 |
| Current retirement savings | 100,000 |
| Monthly contribution before retirement | 500 |
| Annual nominal return (%) | 0 |
| Annual inflation (%) | 0 |
| Monthly retirement spending in today’s money | 1,000 |
| Monthly pension income in today’s money | 0 |
| Result | Projected fund at retirement: 220000 Required fund at retirement: 240000 Funding gap: 20000 Projected monthly spending at retirement: 1000 |
- Check the input labels and enter the example values above.
- Apply the relationship: Grow current savings and month-end contributions to retirement; discount month-start retirement income shortfalls using the real monthly return..
- The result is Projected fund at retirement: 220000 Required fund at retirement: 240000 Funding gap: 20000 Projected monthly spending at retirement: 1000 , rounded for display.
How to interpret your result
Deterministic scenario, not a forecast or safe-withdrawal recommendation. Uses the same constant return before and after retirement; spending and pension grow with inflation. Excludes fees, taxes, market sequence risk and spending after the planning end age. Contributions stay fixed in nominal terms.
Use consistent nominal and inflation-adjusted amounts. A deterministic projection cannot represent market sequence risk, changing taxes or life expectancy. Compare assumptions rather than treating one result as a forecast.
Frequently asked questions
Can a constant-return result show the risk of a market crash?
No. The model excludes the order of returns. Poor returns early in retirement can matter even when the long-term average looks adequate. Test assumptions and seek individual planning advice.
Does a funded projection guarantee retirement income?
No. The result depends on your chosen returns, inflation, income and planning horizon. Real investment outcomes and spending can differ.
When is the retirement calculator useful?
Project retirement savings, inflation-adjusted spending needs and a modelled funding gap. Deterministic scenario, not a forecast or safe-withdrawal recommendation. Uses the same constant return before and after retirement; spending and pension grow with inflation. Excludes fees, taxes, market sequence risk and spending after the planning end age. Contributions stay fixed in nominal terms.
How do I use the retirement calculator?
Enter current age (integer), retirement age (integer), planning end age (integer), current retirement savings, monthly contribution before retirement, annual nominal return (%), annual inflation (%), monthly retirement spending in today’s money, monthly pension income in today’s money. The result updates automatically. Use the units shown beside each input; the example values illustrate the method.
Which formula does this calculator use?
Grow current savings and month-end contributions to retirement; discount month-start retirement income shortfalls using the real monthly return..
What should I check before using the result?
Deterministic scenario, not a forecast or safe-withdrawal recommendation. Uses the same constant return before and after retirement; spending and pension grow with inflation. Excludes fees, taxes, market sequence risk and spending after the planning end age. Contributions stay fixed in nominal terms.
How are results rounded?
Scalar numbers display up to six decimal places, with scientific notation for very large or small values. Text, fraction, date and schedule outputs use the format described on the tool. Intermediate calculations use JavaScript floating-point arithmetic. Keep sensible precision for your measurements.
Further reading
For background on this topic, see Investor.gov: retirement planning ↗. This is a topic reference, not an external review or endorsement of this tool.
Calculators Map editorial process · Updated · Methods and limitations