Time to Reach a Target
Calculates the term until a savings plan (or a lump-sum investment) reaches a target amount.
Enter your own numbers and press "Calculate" – or load an example on the right; "Type in" replays it on the device.
Anyone who postpones a purchase and invests the money instead eventually finances it from the earnings alone – patience plus compound interest replaces a loan.
The first big milestone is closer than you think: consistent monthly saving reaches the goal at a surprising speed – every month of delay pushes it noticeably further back.
→ Story & full explanation: In how many years do you have $100,000?
The unknown is the exponent n. Because n is in the power, you can only get at it via the logarithm: n = ln(ratio)/ln(1+i). The logarithm is the inverse of raising to a power and answers the question "how often must I multiply by q until the target is reached".
Solving the final-value formula for the number of periods.