How to use this calculator
- Enter starting amount, target balance, nominal annual rate (%), number of months, contribution timing.
- Choose a display currency, then select Calculate. Results also update after a brief pause while you edit.
- Read the result with the assumptions below. Export details or save a second scenario to compare your choices.
Formula and method
Assumptions and limitations
Target and deposits are nominal amounts. Returns are constant, fees and taxes are omitted, and deposits remain equal.
Worked example
Starting with 1,000, a 2,200 goal in 12 months at 0% needs 100 per month.
What the result means
If projected starting savings already exceed the goal, the required new contribution is zero. This is different from projecting a chosen SIP contribution.
Common questions
Does this solve for a deposit?
Yes. The target is fixed and the monthly contribution is the unknown.
What if my starting balance exceeds the goal?
No additional deposit is required under the modeled return assumption.
Methodology and transparency
Calculation specification reviewed on 2026-10-14. Mathematical implementation is tested against independent reference fixtures. This does not imply review by a licensed financial professional. Read the testing and precision policy.
Background reference: openstax.org — financial method. FinanceMath implements its own calculator.