Long-run compounding on recurring contributions, in real terms
Results update as you type. Inputs are saved on this device.
Projected value in 20 years
Your starting amount and monthly contributions compound month by month at your expected return. Contributions and balance are charted separately so you can see when growth overtakes what you put in — and the inflation-adjusted value alongside it.
The chart separates principal from investment growth. Early in the projection, new deposits usually drive most of the balance; later, growth can become the larger component. That transition illustrates why time and consistency matter.
The calculator compounds a smooth monthly rate, while real returns arrive unevenly and fees reduce the balance. Do not use an equity-like return for cash needed within a few years.
Inputs are applied directly to standard finance formulas with monthly compounding where relevant. Results are estimates in the selected currency; they do not include every tax, fee, benefit, market event or local rule. Try a conservative and an optimistic case before making a decision.
Last reviewed: August 2026. Primary references include the IRS 2026, SSA, BLS CPI, U.S. DOL, CFPB.
With monthly compounding, A = P(1+r)^n + M × ((1+r)^n − 1) / r, where r is the monthly return and n the number of months.
Divide 72 by the annual return for a rough doubling time — about 9 years at 8%.
At 8% a year, $120,000 of contributions grows to roughly $290,000 — with growth overtaking contributions late in the period.
Nominal dollars lose purchasing power. At 2.5% inflation, a balance 20 years out is worth about 61% of its face value today.
All math runs in your browser and your inputs are never sent to a server. Settings are saved locally and share links encode the state in the URL. For information only — not investment or tax advice.