When to use this calculator
Estimate the unfunded part of a future retirement target under a chosen growth assumption. No new contributions or fees are included in the growth of the current balance.
Explore the savings & interest calculators for other questions in this topic. For a related calculation, use the Rule of 72 Calculator: Approximate how long a sum takes to double at a constant annual return.
PUTTING IT INTO PRACTICE
Retirement Savings Gap: 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 |
|---|---|
| Target retirement balance | 500,000 |
| Current balance | 200,000 |
| Effective annual growth (%) | 0 |
| Years remaining | 10 |
| Result | 300,000 currency units |
- Check the input labels and enter the example values above.
- Apply the relationship: Gap = max(0, target − current balance × (1+r)^years).
- The result is 300,000 currency units, rounded for display.
How to interpret your result
No new contributions or fees are included in the growth of the current balance.
Match the quoted rate to its compounding convention. A nominal rate, effective annual rate and continuous rate are not interchangeable. Contribution timing also matters when interest is included in a future-value model.
Frequently asked questions
Is a future savings value a forecast?
It is a scenario based on your entered rate and contributions. Changing rates, fees, tax or interrupted payments can change the actual outcome.
When is the retirement savings gap calculator useful?
Estimate the unfunded part of a future retirement target under a chosen growth assumption. No new contributions or fees are included in the growth of the current balance.
How do I use the retirement savings gap calculator?
Enter target retirement balance, current balance, effective annual growth (%), years remaining. The result updates automatically. Use the units shown beside each input; the example values illustrate the method.
Which formula does this calculator use?
Gap = max(0, target − current balance × (1+r)^years).
What should I check before using the result?
No new contributions or fees are included in the growth of the current balance.
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 OpenStax: compound interest ↗. This is a topic reference, not an external review or endorsement of this tool.
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