Wealthy PotTSP Calculator
Project your Thrift Savings Plan balance at retirement, including the automatic 1% and the agency matching you earn under FERS or BRS, with a year-by-year breakdown.
The 5% rule is the whole game
Most retirement accounts give you a match set by an employer's policy. The TSP is different: the agency money is written into law. Under 5 U.S.C. § 8432(c), your agency contributes 1% of basic pay automatically, matches your first 3% dollar-for-dollar, and matches the next 2% at fifty cents on the dollar.
Add it up and a 5% contribution collects 5% of pay in agency money — a 100% immediate return on what you put in. Contribute 4% and you collect 4.5%. Contribute nothing and you still get the automatic 1%, but you leave the entire 4% match behind.
What the projection assumes
- Contributions grow at a steady annual rate, compounded monthly. Real markets do not move in a straight line, so treat the ending balance as illustrative rather than a forecast.
- Your basic pay stays flat. Raises, promotions and locality adjustments would push the real number higher.
- Agency money is included in the balance but is always traditional (pre-tax), even when your own contributions go to the Roth TSP.
- Figures are nominal — before taxes, before inflation.
Where TSP fees fit in
The TSP's administrative expenses are among the lowest available anywhere, which is why the usual advice is to capture the full match before routing money elsewhere. Once you are at 5%, the next decision is whether additional savings belong in the TSP, an IRA, or a taxable account — a question of tax treatment and flexibility rather than cost.
Before you change your contribution
- Get to 5% first if you are under it. Nothing else in a federal benefits package returns as much.
- Spread contributions evenly across pay periods so you do not hit the annual limit early and forfeit match in the final months of the year.
- Check whether your contribution election is a percentage or a flat dollar amount; flat amounts silently drift away from 5% every time your pay changes.
- If you are close to retirement, read the full TSP guide on withdrawal options before modelling a drawdown.
Frequently Asked Questions
How much does the government contribute to my TSP?
Under FERS, your agency adds 1% of your basic pay automatically, whether or not you contribute anything. On top of that it matches your own contributions dollar-for-dollar on the first 3% of basic pay, then 50 cents on the dollar for the next 2%. Contribute 5% and you collect the full 4% match, for 5% of pay in agency money. Anything you contribute above 5% is not matched.
What happens if I contribute less than 5%?
You give up part of the match. At 3% you get 3% matched plus the automatic 1%; the half-rate tier on the next 2% goes unclaimed. The calculator shows the exact yearly dollar amount you are leaving behind.
Is military TSP matching different?
The tiers are the same under the Blended Retirement System, but the timing is not. The automatic 1% starts after 60 days of service, while service matching only begins after 24 months. CSRS participants can contribute to the TSP but receive no automatic or matching contributions at all.
How much can I put in the TSP in 2026?
The elective deferral limit is $24,500. If you are 50 or older you can add an $8,000 catch-up for $32,500 total, and at ages 60 to 63 the catch-up is $11,250 for $35,750 total. These are IRS limits that cover your 401(k), 403(b) and TSP deferrals combined.
Should I worry about hitting the limit early?
Yes. Matching is calculated per pay period, not annually. If large contributions max you out before the final pay period, you stop contributing, and in the pay periods that follow there is nothing for the agency to match. Spreading contributions across all 26 pay periods protects the full match.
Does this calculator account for taxes or inflation?
No. Results are nominal, before taxes and inflation. Traditional TSP contributions are pre-tax and taxed on withdrawal; Roth TSP contributions are after-tax and qualified withdrawals are tax-free. Agency contributions always go into the traditional balance, even if your own money goes to Roth.