Cost of Waiting to Invest
Cost of Waiting to Invest Calculator
What this calculator does
This calculator shows the real cost of delaying investments. Time in the market is usually the biggest driver of wealth.
The math, with a worked example
Future value = monthly contribution × (((1 + monthly rate)^months − 1) ÷ monthly rate). The difference = later-start value − now-start value. Investing $300 per month starting at age 25 versus age 35 at 7% annual return can mean a difference of over $200,000 by retirement.
Why this matters
Waiting 10 years to start investing costs more than any fee you'll ever pay: $300 a month from 25 versus 35 at 7% is a 6-figure difference at retirement. Time in the market is the one input you can never buy back.
Methodology and transparency
Future value = contribution × (((1 + monthly rate)^months − 1) ÷ monthly rate), computed for both start dates; the gap is the cost of waiting. The rate assumption owns the magnitude (7% long-run equity average; run 4% for caution) but not the conclusion — the early start wins at every positive rate, and the gap widens with horizon. Everything runs in your browser; no data is sent or stored.
Last reviewed: 2026-08-08
Common questions
Why does starting early matter so much?
Compound interest means early contributions earn returns for longer, and those returns also earn returns.
What if I start late?
You may need to contribute more per month to catch up. The calculator shows exactly how much.
Is 7% a realistic return?
It is a common long-term average for a diversified stock portfolio, but actual returns vary.