Retirement Investment Calculator

How to use

1. Enter the lump sum you are investing today.
2. Add the monthly contribution and the years you will stay invested.
3. Set an assumed annual return and an expected inflation rate.
4. Compare the nominal future value with its value in today's dollars.

General information only — not medical, financial or legal advice. Figures cross-checked against public official sources (IRS / HMRC / NHS / WHO guidance); content last reviewed September 2026. For decisions that matter, confirm with a licensed professional in your country.

About this tool

This investment calculator answers a question plain growth tools skip: what will the balance actually buy? Enter an initial lump sum, monthly contributions, an assumed return, years, and expected inflation; the engine compounds monthly for the nominal future value, then divides by the inflation factor to restate the ending balance in today's purchasing power. At the defaults, 50,000 dollars plus 800 dollars monthly at 7.5 percent for 25 years projects near 1,026,000 dollars nominally, but about 553,000 dollars once 2.5 percent inflation is priced in. The gap is the whole point: nominal totals flatter long horizons. Both views share one contribution ledger, so the growth line reflects the same deposits in either frame. Outputs are illustrative projections at constant rates; inflation and returns vary; verify tax treatment for your account type; not investment advice.A flat return also ignores how allocations change. Most investors glide from stock-heavy portfolios toward bonds as retirement approaches, which usually lowers both expected return and volatility; this tool applies one rate throughout. Expense ratios compound against you the same way returns compound for you, so subtracting fund fees from the assumed return before running the numbers gives a more honest picture.

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