TSP Calculator
Your pay, your contribution rate, and what the agency adds
Your result will appear here
Fill in the fields on the left and this updates as you type.
Know what this estimate is based on
- Jurisdiction
- General mathematical model
- Scope and limitations
- Long-range scenario, not a guarantee. Small changes in returns, inflation, fees, taxes, and withdrawal timing can materially change the result.
- Source links checked
- Jul 30, 2026
Built and regression-tested by Smart Tools Lab. It has not been individually reviewed by a licensed financial, tax, or legal professional.
How to use
- 01
Enter your annual basic pay. Every agency figure is a share of it — not overtime, not special or incentive pay for a service member.
- 02
Enter what you contribute as a percentage of basic pay. Below 5% you are leaving agency money behind; the calculator prices exactly how much.
- 03
Enter your age and your years of federal service. Age opens the catch-up at 50, and service runs the vesting clock on the automatic 1%.
- 04
Add your balance, the years to retirement and an expected return. Then enter the expense ratio of the fund you would roll into if you left — that is what the TSP's own ratio is being compared with.
- 05
Read the projected balance, the agency money it contains, and the table showing which tier each agency dollar came from.
Formula
Agency contribution = 1% of basic pay automatically, plus 100% of the first 3% of pay you contribute, plus 50% of the next 2%. So the agency maximum is 5% of basic pay, reached when you contribute 5%. Your own contributions are capped at $24,500 for 2026, plus $8,000 from age 50 or $11,250 at 60-63. Balance = current balance and each year's total contribution compounded at your expected return less the expense ratio.
Example
A GS-12 on $95,000 of basic pay contributing 5%: $4,750 of her own money, plus $950 automatic, plus $2,850 matched dollar-for-dollar on the first 3%, plus $950 on the next 2% — $4,750 from the agency, exactly matching her own contribution. Drop to 3% and the agency gives $950 + $2,850 = $3,800, leaving $950 on the table every year. On a $120,000 balance with 20 years to go at 7%, the TSP's 0.05% leaves about $847,000 while a 0.60% retail fund leaves about $780,000 — the expense ratio alone is worth roughly $67,000.
Definitions
- Basic pay
- The salary the agency formula is computed on — the figure on your SF-50 or Leave and Earnings Statement. Not overtime, and for a service member not special or incentive pay.
- Agency automatic contribution
- 1% of basic pay paid into your account whether or not you contribute anything. The only piece with a vesting requirement.
- Agency matching contribution
- Dollar-for-dollar on the first 3% of pay you contribute, then 50 cents on the dollar for the next 2%. Vested immediately.
- Spillover
- The TSP's handling of catch-up money: once you pass the annual elective deferral limit, further contributions automatically count as catch-up rather than stopping.
- Blended Retirement System
- The uniformed-services retirement structure that pairs a reduced pension with TSP agency contributions. Automatic from day 61 of service, matching from the 25th month.
Good to know
Three contributions wearing one name
Almost every article about the Thrift Savings Plan describes a '5% match', and that phrase gets the answer wrong in both directions. The agency contribution is three separate things. There is an automatic contribution of 1% of basic pay, paid into your account whether you contribute anything at all — a federal employee who has never made an election still has money going in. There is then a dollar-for-dollar match on the first 3% of pay you contribute. And there is 50 cents on the dollar for the next 2%. Contribute 5% of basic pay and the agency contributes 5% too, which is why the shorthand exists; contribute nothing and you still get 1%, which the shorthand denies; contribute 4% and you get 1% + 3% + 0.5% = 4.5%, which the shorthand cannot express. A 401(k) calculator applied to a federal employee therefore understates the low end and overstates the middle, and the difference over a career is real money.
The per-pay-period trap and the vesting clock
Two rules in the plan's administration catch people who have done everything else right. The first is that matching is computed per pay period rather than per year. Contribute aggressively enough to hit the $24,500 annual limit in October and your contributions stop for the remaining pay periods — and so does the match on them, permanently, with no true-up at year end. The fix is arithmetic rather than restraint: divide the amount you intend to contribute across all 26 pay periods rather than front-loading it. The automatic 1% keeps arriving either way. The second rule is vesting, and it is narrower than people fear. Your own contributions and every matching dollar are yours from the first pay period. Only the automatic 1% has a clock on it — three years of federal civilian service for most FERS employees, two for certain positions and for uniformed-services members under the Blended Retirement System. Leaving before it runs out forfeits that piece and its earnings, and nothing else.
The cheapest retirement plan in the country
The TSP's net expense ratio runs around five hundredths of one percent — check the current figure on tsp.gov, because it moves a little each year with the plan's own costs. A typical retail target-date fund in an IRA runs somewhere between 0.30% and 0.75%. That gap sounds trivial and is not, because a fee is charged on the entire balance every year rather than on new money, so it compounds against you exactly as returns compound for you. On a $120,000 balance with twenty years and $9,500 a year going in at 7%, the difference between 0.05% and 0.60% is roughly $67,000. This is the arithmetic behind every rollover pitch a separating federal employee receives, and it is why the honest answer to 'should I roll my TSP out?' usually starts with what the receiving account charges. An IRA buys wider investment choice and easier partial withdrawals. It also, for anyone separating at 55 or later, destroys the age-55 exception that would have let them reach the money penalty-free — that exception attaches to employer plans and section 72(t)(3)(A) expressly denies it to IRAs.
Roth TSP, and the pot you cannot make tax-free
The TSP holds both a traditional and a Roth balance, and a service member or federal employee can direct their own contributions to either. What cannot be directed is the agency's money: every automatic and matching dollar goes into the traditional side, whatever you have chosen for yourself. So someone who has contributed exclusively to Roth TSP for a decade still holds two balances with two tax treatments, and a withdrawal draws proportionally from both — a Roth TSP does not produce a tax-free retirement on its own. Two further points for the uniformed services. Special and incentive pay may be contributed but is never matched; only basic pay is. And contributions made from pay earned in a combat zone go into a traditional balance tax-free, which makes them one of very few genuinely tax-free contributions in the entire code — money that was never taxed going in and is taxed only on its earnings coming out.
Frequently asked questions
How does the TSP match actually work?
It is three separate things, not one percentage. First, an automatic agency contribution of 1% of basic pay, paid whether or not you contribute a cent. Then a dollar-for-dollar match on the first 3% of pay you contribute. Then 50 cents on the dollar for the next 2%. Contribute 5% of basic pay and you collect the whole thing — a 5% agency contribution on top of your own 5%, which is an immediate 100% return before the market does anything.
What happens if I contribute more than 5%?
Nothing extra from the agency. The match runs out at 5% of pay and stops. Contributing above it is still worth doing — it is tax-advantaged money in a plan with an expense ratio around 0.05% — but it is unmatched, and if a higher-cost debt or an unfunded emergency fund is competing for the same dollar, that is the comparison to run.
I maxed out early last year and my match stopped. Why?
The match is computed per pay period, not per year. Contribute so aggressively that you hit the $24,500 annual limit in October and your contributions stop for the remaining pay periods — and so does the matching on them, permanently. Spreading the deferral across all 26 pay periods is the fix. The automatic 1% keeps coming either way.
Am I vested? What does that mean here?
Only the automatic 1% has a vesting clock. Your own contributions and every matching dollar are yours from the first pay period. The automatic contribution needs three years of federal civilian service — two years for certain positions, and two years for uniformed-services members under the Blended Retirement System. Leaving early forfeits that piece and its earnings, and nothing else.
Should I roll my TSP into an IRA when I leave?
The fee arithmetic argues strongly against it. The TSP's net expense ratio runs around 0.05%, against roughly 0.30% to 0.75% for a typical retail target-date fund, and a fee difference compounds against the entire balance every year rather than against new money only. An IRA buys wider investment choice and easier partial withdrawals; the TSP keeps the cost floor and, for anyone separating at 55 or later, the age-55 exception that a rollover to an IRA destroys.
If I choose Roth TSP, is everything tax-free?
No. Every agency dollar — the automatic 1% and all the matching — goes into the traditional side of the account regardless of what you choose for your own contributions. So a Roth contributor still ends up with two balances and two tax treatments, and a withdrawal draws proportionally from both.
Does this apply to service members?
Under the Blended Retirement System, yes, with different timing: the automatic 1% starts after 60 days of service and the matching tiers start at the beginning of the 25th month, both running to 26 years of service. Special and incentive pay can be contributed but is never matched — only basic pay is. Contributions from combat-zone pay to a traditional balance go in tax-free, one of the few genuinely tax-free contributions in the code.