Retirement Savings Projector (Compound Growth)

How this calculation works

This projection compounds monthly at your chosen annual return and adds your monthly contribution — the same math behind every retirement calculator, but transparent.

The 4% rule converts the projected balance into an annual (and monthly) retirement income figure, so you can compare it against your expected spending.

How this Retirement Savings Projector (Compound Growth) works — 2026 guide

Compound interest is the closest thing to a financial superpower, and this projector makes it concrete: starting balance, monthly contributions, annual return, and years to retirement become a projected balance — and the 4% rule turns that balance into an annual retirement income. Because 2026 raised the 401(k) cap to $24,500 and the IRA cap to $7,500, the tool also nudges you toward contribution levels that actually max the tax-advantaged space.

How to use it in 3 steps

1. Enter your current retirement balance, monthly contribution, expected annual return, and years to retirement.
2. The calculator compounds monthly and adds contributions each period.
3. Read your projected balance, total contributed, growth, and the income it supports under the 4% rule.

Who this is for

Anyone estimating whether they are on track, comparing contribution amounts, or testing “what if I increase by $100/month”. Pair with the [RMD estimator](/tools/rmd-estimator/) to plan the withdrawal side.

Data sources & authoritative references

This calculator is built on official U.S. rules and published statistics. Key sources:

• IRS — 401(k) contribution limits (2026: $24,500, +$8,000 catch-up at 50+)
• IRS — IRA contribution limits (2026: $7,500, +$1,100 catch-up)
• BLS — Long-term stock market returns (S&P 500)