We compare the future value at retirement of the same monthly contribution started today versus started after a delay. The difference is the "cost" of waiting — driven almost entirely by the compounding years you give up.

Step by step

1. We treat your contribution as a level monthly deposit (an ordinary annuity).
2. Start now: the deposit compounds for all the months until retirement.
3. If you wait: the same deposit compounds only for the months that remain after the delay.
4. Cost of waiting = (start-now value) − (delayed value).

The math

FV = PMT · (((1+i)^n − 1) ÷ i), with i = annualReturn/12 and n the number of contributing months; cost = FV(now) − FV(delayed).

Sources & assumptions

• Public-domain future-value-of-an-ordinary-annuity formula. The growth rate is a shown, configurable assumption.

Note: Nothing proprietary.

1. An educational estimate using a level monthly contribution and the growth assumption shown with your results; actual returns vary and are not guaranteed. Not advice.