TSP Calculator (Thrift Savings Plan)

Federal employees and uniformed service members rely on the Thrift Savings Plan to build the bulk of their retirement nest egg, and this tool turns your own numbers into a concrete projection. Feed it your salary, the share of pay you set aside, and an assumed rate of return, and it shows your contributions, the agency money you earn, and the balance those amounts could grow into over time. The 2026 limits and matching rules are built in, so the picture you see reflects current law rather than a generic estimate.

The projection starts with the 2026 elective deferral limit of $23,000 for regular contributions, plus the catch-up allowance of $7,500 once you reach age 50. Agency money follows the established formula: an automatic 1% contribution regardless of what you put in, a dollar-for-dollar match on the first 3% you defer, and 50 cents per dollar on the next 2%. Contribute at least 5% of your own pay and you capture the full match the government offers.

Treat the growth rate as a planning assumption, not a promise; real-world returns swing from year to year and can land well above or below your input. Inflation deserves attention too, since a balance that looks large in future dollars buys less than the same figure would today. The costliest oversight is contributing below 5%, because anything short of that simply forfeits matching dollars you were entitled to collect.