A worked example
Starting with $10,000 and adding $200 a month at 7% for 20 years solves to a future value of roughly $144,573. Switch the mode to solve for present value or time instead, and the same four remaining numbers solve for whichever one you need.
Frequently asked questions
Why does this avoid the usual negative-number convention financial calculators use?
Traditional financial calculators (and many physical ones) use negative numbers for money paid out and positive for money received, which trips up even experienced users. This tool only models one direction — money flowing into a balance that grows — so every number stays positive and intuitive.
What's the practical use of solving for 'time'?
It answers 'how long until I have $X', given a starting balance, ongoing contributions and a rate — the same question behind any savings goal, just generalized into time-value-of-money terms.
This calculator provides estimates for general informational purposes only and is not financial advice.