The TSP calculator projects your Thrift Savings Plan balance at retirement from your current balance, pay, contribution rate, raises and expected return. It includes the FERS/BRS agency match (1% automatic plus up to 4% matching) and the 2026 IRS limit of $24,500. Contributing at least 5% gets you the full 5% from your agency.
How to use this calculator
- Enter your current TSP balance from your latest statement or tsp.gov account.
- Enter your current age and the age you plan to retire.
- Enter your annual basic pay and the percentage you contribute.
- Set an expected annual raise and an expected return. The return is your assumption — see the fund returns below for context.
- Pick FERS/BRS if you receive agency contributions, or None for CSRS and other no-match cases.
- Read your projected balance, the split between your money, agency money and growth, and the year-by-year table.
How it's calculated
For each year until retirement:
- Your contribution = pay × your % — capped at the IRS limit for your age ($24,500 under 50, $32,500 at 50+, $35,750 at 60–63, per IRS Notice 2025-67).
- Agency contribution = pay × (1% + 100% of your first 3% + 50% of your next 2%), per TSP.gov.
- Balance = last year's balance × (1 + return) + contributions × (1 + return ÷ 2). Contributions arrive every paycheck, so on average they earn half a year of growth in the year they go in.
- Pay rises by your raise rate for the next year.
The “4% rule monthly income” is 4% of the final balance ÷ 12 — a rough starting withdrawal, based on the Bengen and Trinity research on 30-year retirements.
TSP matching chart
| You contribute | Automatic 1% | Agency match | Total into TSP |
|---|---|---|---|
| 0% | 1% | 0% | 1% |
| 1% | 1% | 1% | 3% |
| 2% | 1% | 2% | 5% |
| 3% | 1% | 3% | 7% |
| 4% | 1% | 3.5% | 8.5% |
| 5% | 1% | 4% | 10% |
| 10% | 1% | 4% | 15% |
Worked examples
Returns in these examples are assumptions for illustration.
Age 30, $70,000 salary, 5% contribution
Starting with $25,000, a 2% yearly raise and a 7% return, the balance at 60 is about $1,030,856. You put in $141,988, your agency adds $141,988, and growth accounts for $721,879.
The cost of contributing only 3%
At 3% you get 4% from the agency instead of 5%. The balance at 60 falls to about $778,691 — $252,165 less. Contributing nothing still earns the automatic 1%, but only reaches about $274,361.
Age 50, maxing out with catch-up
With $150,000 saved, a $110,000 salary and 35% elected, contributions are capped at the age limit each year. With a 6% return, the balance at 62 is about $978,809.
TSP growth calculator: how a Thrift Savings Plan balance grows
The chart under the results plots your projected TSP balance by age against the money that went in (your starting balance plus your and your agency's contributions). The widening gap between the two lines is investment growth. In the first example, growth is $721,879 of the $1,030,856 total at 60 — 70% of the balance — which is why the early years of contributions matter most.
TSP balance by contribution rate
Balance after 30 years for the first example (age 30 to 60, $70,000 salary, 2% raises, 7% return, FERS match).
| You contribute | Agency adds | Balance at 60 |
|---|---|---|
| 0% | 1% | $274,361 |
| 1% | 2% | $442,471 |
| 3% | 4% | $778,691 |
| 5% | 5% | $1,030,856 |
| 8% | 5% | $1,283,021 |
| 10% | 5% | $1,451,131 |
| 15% | 5% | $1,871,405 |
TSP balance by return and years to retirement
Starting from $0 with a $70,000 salary, 5% contributions plus the full match and 2% raises.
| Start age → years | 4% return | 5% return | 6% return | 7% return | 8% return |
|---|---|---|---|---|---|
| 25 → 30 years | $511,237 | $600,447 | $708,766 | $840,549 | $1,001,157 |
| 30 → 25 years | $366,007 | $417,525 | $477,890 | $548,711 | $631,888 |
| 35 → 20 years | $251,748 | $279,191 | $310,244 | $345,404 | $385,235 |
| 40 → 15 years | $162,462 | $175,323 | $189,387 | $204,767 | $221,591 |
| 45 → 10 years | $93,266 | $98,034 | $103,077 | $108,408 | $114,045 |
TSP fund returns for context
The TSP Fund Information booklet reports average annual returns since inception through December 31, 2025, after expenses and before inflation: C Fund 11.34%, S Fund 9.42%, I Fund 6.01% and G Fund 4.65%. A long-run return in the calculator should reflect your mix of funds (or your L Fund) and allow for bad years; these past averages are not a forecast.
Rules that change your result
- Automatic enrollment. New and rehired employees since October 1, 2020, are enrolled at 5% of basic pay unless they choose otherwise (TSP.gov). Check your LES — if you were enrolled earlier at 3%, you may be missing part of the match.
- Vesting. Your contributions and the match are yours immediately. The 1% automatic contribution vests after 3 years for most FERS employees (2 years in some positions), per TSP Bulletin 15-1.
- Hitting the limit early. The match is paid on each pay period's contribution. If you max out before December, you lose the match for the remaining pay periods, so spread contributions across the year.
- Roth catch-up rule. From 2026, if your 2025 wages were over $150,000, catch-up contributions must be Roth (IRS Notice 2025-67).
- Traditional vs Roth. The calculator shows a pre-tax balance. Traditional TSP withdrawals are taxed in retirement; Roth TSP rules differ. It doesn't model taxes.
Limits of this projection
The projection uses one steady return, a steady raise and no breaks in service, loans or withdrawals. Real markets vary year to year, and a TSP loan or a gap in service lowers the result. Use it to compare choices — such as 3% versus 5% — rather than as a promise. This page is general information, not financial or retirement advice; for your own benefits, check your TSP account, your agency benefits office or the resources on tsp.gov.
Related: once you retire, see how long your TSP balance will last, check your annual leave with the PTO accrual calculator, or convert your salary with the hourly to salary calculator.
Not a federal employee? The 401(k), 403(b) and 457 calculator applies the same 2026 limits with your employer's match. Thinking of taking money out early? See the 401(k) early withdrawal calculator. For short-term cash, compare the Treasury bill calculator.
Frequently asked questions
How does the TSP match work?
FERS employees and BRS service members get 1% of basic pay automatically, plus a dollar-for-dollar match on the first 3% they contribute and 50 cents per dollar on the next 2%. Contribute 5% and you receive the full 5%. BRS members get the 1% after 60 days of service and matching after 2 years.
How much does the agency put in if I contribute 4%?
3.5% in matching plus the 1% automatic, so 4.5% from the agency and 8.5% of your pay in total. At 5% you would get the full 5%.
What is the TSP contribution limit for 2026?
For 2026 the elective deferral limit is $24,500, plus $8,000 catch-up at age 50+ ($11,250 at ages 60–63), so up to $32,500 or $35,750. Agency contributions don't count toward it. Starting in 2026, if your 2025 wages were over $150,000, your catch-up contributions must go to Roth TSP.
What return should I assume?
Through December 31, 2025, TSP reports average annual returns since inception of 11.34% for the C Fund (since 1988), 9.42% for the S Fund and 6.01% for the I Fund (since 2001), and 4.65% for the G Fund (since 1987) — all before inflation. Past returns don't guarantee future results; the G Fund can't lose principal.
How much will my TSP be worth in 30 years?
As an example, starting at age 30 with $25,000, a $70,000 salary rising 2% a year, 5% contributions plus the full match and a 7% return, the projection reaches about $1,030,856 at age 60. Your figure depends mostly on your contribution rate and return.
Is this a TSP growth calculator or a Thrift Savings Plan savings calculator?
Both. It is a Thrift Savings Plan calculator that projects growth year by year: enter your balance, pay, contribution rate, raise and expected return, and it shows your balance at retirement, the split between your contributions, agency contributions and growth, and a chart of the balance by age.
Am I automatically enrolled in the TSP?
If you began or rejoined federal service on or after October 1, 2020, your agency automatically enrolled you at 5% of basic pay into traditional TSP, unless you changed or stopped it. BRS members are enrolled after 60 days. Those who started between August 1, 2010, and September 30, 2020, were enrolled at 3%.
When am I vested in the TSP?
You are always vested in your own contributions and in agency matching contributions. The 1% agency automatic contribution vests after 3 years of service for most FERS employees, or 2 years in certain positions. If you leave before that, the 1% and its earnings are forfeited.
What happens to the match if I hit the limit early?
Matching is based on what you contribute each pay period. If you reach the IRS limit before the end of the calendar year, your contributions stop and so does the match for the remaining pay periods. TSP advises making sure you don't reach the limit before the end of the calendar year.
Does the calculator include catch-up contributions?
Yes. From age 50 your contribution is capped at $32,500 a year instead of $24,500, and at $35,750 for ages 60–63. TSP says catch-up contributions can also be matched, up to 5% of salary.
Sources & method
- TSP.gov — what is a contribution? (agency automatic and matching)
- TSP.gov — making contributions (automatic enrollment)
- TSP Bulletin 15-1 — vesting requirements
- TSP.gov — 2026 contribution limits
- IRS — 401(k) limit increases to $24,500 for 2026 (IR-2025-111)
- IRS Notice 2025-67 — 2026 limits incl. Roth catch-up wage threshold
- TSP Fund Information booklet (returns through Dec 31, 2025)
Results are estimates for general information. Found an error? It helps everyone — see our methodology.