TSP Calculator - Free Online Tool

Project your Thrift Savings Plan retirement balance with BRS matching, catch-up contributions, and fund allocation.

The Thrift Savings Plan (TSP) is the federal government's version of a 401(k) retirement savings plan, available to all military service members, federal civilian employees under FERS, and qualifying retirees. With over $800 billion in assets and an expense ratio of just 0.055%, the TSP is one of the best retirement vehicles available anywhere — but only if you contribute enough to capture your full employer match and understand how the Blended Retirement System (BRS) works. For military members who entered service on or after January 1, 2018, the Blended Retirement System automatically enrolls you in TSP and provides a generous matching contribution formula: 1% automatic contribution after 60 days of service, dollar-for-dollar matching on the first 3% you contribute, and 50 cents on each dollar for the next 2%. This means if you contribute just 5% of your basic pay, the government adds another 5%, giving you a 10% total contribution rate. That matching leverage is the most powerful wealth-building tool available to service members. Under the 2026 IRS contribution limits, you can defer up to $24,500 per year from your paycheck. If you are age 50 or older, you qualify for an additional $8,000 catch-up contribution, bringing your total to $32,500. Service members between ages 60 and 63 benefit from a special SECURE Act 2.0 super catch-up provision allowing an additional $11,250 instead of $8,000, for a maximum of $35,750. If you deploy to a combat zone and receive tax-exempt combat pay, you can contribute up to the annual additions limit of $72,000 — and if you contribute those tax-exempt dollars to a Roth TSP, you achieve a triple tax benefit: no tax on the income, no tax on the growth, and no tax on qualified withdrawals. Choosing the right TSP fund allocation dramatically affects your retirement balance. The G Fund holds US Treasury securities with near-zero principal risk (~4.1% historical return). The F Fund tracks the US bond market (~5.8%). The C Fund mirrors the S&P 500 (~10.4% historical return) and is the workhorse of long-term TSP growth. The S Fund covers small and mid-cap stocks (~9.6%) while the I Fund covers international equities (~6.2%). Lifecycle (L) Funds automatically adjust risk over time and are a solid default for hands-off investors. Most financial advisors recommend a C/S/I mix for younger investors seeking growth, shifting toward G/F as retirement approaches. A critical pitfall to avoid: if you max out your TSP contributions too early in the calendar year, you stop contributing — and the government stops matching — for the remaining months. Because BRS matching is paid each pay period, not annually, a service member who hits the $24,500 cap in October loses two months of agency match. Our calculator shows you exactly how much to contribute each month to hit the annual limit in December, preserving every dollar of matching. Our TSP calculator handles all of this: enter your current balance, salary, contribution rate, years to retirement, and expected fund allocation to project your balance at retirement. Switch between percentage and dollar contribution modes, enable the combat zone option to see elevated limits, turn on the BRS versus Legacy High-3 comparison to evaluate which retirement system benefits you more, and export your full year-by-year projection as a CSV file for deeper analysis.

Understanding the TSP

What Is the Thrift Savings Plan?

The Thrift Savings Plan is a defined-contribution retirement savings plan established by the Federal Employees' Retirement System Act of 1986. It functions similarly to a private-sector 401(k), allowing participants to invest pre-tax (Traditional) or after-tax (Roth) dollars across a range of index funds. The TSP is administered by the Federal Retirement Thrift Investment Board and is open to all active military members, federal civilian employees under FERS or CSRS, and eligible members of uniformed services. With an expense ratio of approximately 0.055%, the TSP has among the lowest investment costs of any retirement plan in the world. Funds grow tax-deferred (Traditional) or tax-free (Roth) until retirement, and participants can borrow against their balance or make hardship withdrawals under certain conditions.

How Are TSP Projections Calculated?

TSP balance projections use the future value of a present lump sum plus the future value of an annuity (periodic contributions). The formula compounds monthly for accuracy: FV_balance = current_balance × (1 + r/12)^(n×12), where r is the annual return rate and n is years. Contributions are compounded as: FV_contrib = monthly_contribution × [((1 + r/12)^(n×12) - 1) / (r/12)]. BRS employer match is calculated each year as a percentage of salary: 1% auto-contribution plus dollar-for-dollar on first 3% you contribute, plus 50 cents per dollar on the next 2%, capping at 5% total employer contribution. The weighted average return across fund allocations is: Σ(fund_pct × fund_return). Annual salary increases are applied each year to scale contributions proportionally.

Why TSP Contributions Matter

Compounding over a 20–30 year career turns modest monthly contributions into life-changing wealth. A service member contributing 5% of a $55,000 basic pay salary (with full 5% BRS match) starting at age 25 and retiring at 45 can accumulate over $300,000 even at a conservative 6% return — solely from TSP. Add the C Fund's historical 10.4% return and that number climbs dramatically. Perhaps more important: the BRS match is free money with immediate vesting on match contributions, making it the highest-return 'investment' available. Every dollar not contributed to capture the full 5% match is money permanently left on the table. For those under the Legacy High-3 system, while there is no TSP match, voluntary contributions still benefit from the same tax-advantaged compounding and ultra-low fee structure.

Important Limitations and Disclaimers

TSP projections are estimates based on assumptions you enter; actual results will differ based on market performance, actual salary increases, and changes to contribution rates over time. Past performance of TSP funds (particularly the C, S, and I Funds) does not guarantee future results. All government and agency matching contributions are deposited into the Traditional (pre-tax) TSP regardless of whether you elect Roth contributions for your own deferrals. Withdrawals before age 59½ may incur a 10% early withdrawal penalty plus ordinary income taxes (except from Roth TSP if the account is at least 5 years old and you are over 59½ or disabled). Loan repayments do not count toward the annual elective deferral limit. The calculator does not account for TSP loan activity, TSP contribution limits being indexed for future inflation, or potential legislative changes to contribution limits.

TSP Projection Formulas

Future Value of Current Balance

FV_balance = Current Balance × (1 + r/12)^(n × 12)

Compounds your existing TSP balance monthly over n years at annual return rate r. This represents the growth of money already in your account without additional contributions.

Future Value of Contributions (Annuity)

FV_contrib = Monthly Contribution × [((1 + r/12)^(n × 12) − 1) / (r/12)]

The future value of a series of equal monthly contributions compounded at rate r over n years. This is the standard future value of an ordinary annuity formula.

BRS Employer Match

Match = 1% auto + 100% match on first 3% + 50% match on next 2% = up to 5% of basic pay

The Blended Retirement System provides a 1% automatic contribution plus matching: dollar-for-dollar on the first 3% you contribute, and 50 cents per dollar on the next 2%. Contributing 5% captures the full 5% employer match for a total 10% contribution rate.

Tax Savings (Traditional TSP)

Annual Tax Savings = Annual Contribution × Marginal Tax Rate

Traditional TSP contributions reduce your current taxable income. At a 22% marginal rate, contributing $24,500 saves $5,390 in federal taxes this year — though withdrawals in retirement will be taxed as ordinary income.

TSP Reference Tables

TSP Fund Options and Historical Returns

The five individual TSP funds and Lifecycle fund series, with approximate historical average annual returns since inception.

Fund	Investment Type	Historical Return	Risk Level
G Fund	U.S. Treasury Securities	~4.1%	Very Low (no principal risk)
F Fund	U.S. Bond Market Index	~5.8%	Low to Moderate
C Fund	S&P 500 Index	~10.4%	Moderate to High
S Fund	Small/Mid-Cap Stock Index	~9.6%	High
I Fund	International Stock Index	~6.2%	High
L Funds	Lifecycle (auto-rebalancing)	Varies by target date	Adjusts over time

TSP Contribution Limits (2026)

IRS elective deferral and catch-up contribution limits for the Thrift Savings Plan in tax year 2026.

Category	Annual Limit	Notes
Standard Elective Deferral	$24,500	Applies to all participants under age 50
Age 50+ Catch-Up	$8,000	Additional allowance for participants age 50–59 or 64+
Age 60–63 Super Catch-Up	$11,250	SECURE Act 2.0 enhanced catch-up for ages 60–63
Total (under 50)	$24,500	Standard maximum
Total (age 50+)	$32,500	$24,500 + $8,000 catch-up
Total (age 60–63)	$35,750	$24,500 + $11,250 super catch-up
Combat Zone (Annual Additions)	$72,000	Bypasses elective deferral cap for tax-exempt pay

TSP Growth Worked Examples

E-5 with BRS — 5% Contribution Over 20 Years

An E-5 earning $55,000 annual basic pay contributes 5% to TSP with full BRS matching. Starting balance is $0, expected return is 7% (blended C/S/I allocation), and annual pay raises average 2%.

Monthly contribution: $55,000 × 5% / 12 = $229.17

Monthly BRS match: $55,000 × 5% / 12 = $229.17 (1% auto + 3% match + 1% on next 2%)

Total monthly going into TSP: $458.34

Year 1 total contributions: $458.34 × 12 = $5,500.08

With 2% annual raises, contributions grow each year

After 20 years at 7% return: projected balance ≈ $301,000

Of that: ~$134,000 from your contributions, ~$134,000 from BRS match, ~$33,000 from investment growth

Contributing just 5% of basic pay with full BRS match grows to approximately $301,000 over a 20-year career at 7% return — demonstrating the power of matching and compound growth.

Roth vs Traditional TSP — 22% Tax Bracket

Compare Roth and Traditional TSP for a service member contributing $24,500/year for 20 years at 8% return. Current marginal tax rate: 22%. Expected retirement tax rate: 15%.

Traditional TSP: $24,500/year grows to ~$1,208,000 (pre-tax). After 15% tax at withdrawal: ~$1,026,800 after-tax value.

Roth TSP: After-tax contribution = $24,500 × (1 − 0.22) = $19,110 equivalent out-of-pocket cost. But $24,500 goes in (you pay tax upfront).

Roth balance at retirement: ~$1,208,000 — ALL tax-free on qualified withdrawal.

Traditional saves $5,390/year in taxes now (22% × $24,500) but costs 15% on the full balance later.

Roth is better if your retirement tax rate is higher than or equal to your current rate.

If your retirement tax rate (15%) is lower than your current rate (22%), Traditional TSP provides ~$181,200 more in after-tax value. If rates are equal or higher in retirement, Roth wins.

How to Use the TSP Calculator

Select Your Retirement System

Choose BRS (Blended Retirement System) if you joined the military on or after January 1, 2018 — this unlocks the 1% automatic + up to 4% matching formula. Choose Legacy High-3 if you joined before 2018 (no TSP employer match). Choose 'No Match' for non-matched civilian accounts.

Enter Your Salary and Contribution Rate

Enter your current annual basic pay or salary. Then set your contribution as either a percentage of pay or a fixed dollar amount. To capture the full BRS match, contribute at least 5% of basic pay. The calculator will also show you the exact monthly amount to contribute so you hit the $24,500 annual limit evenly in December without losing monthly match.

Configure Fund Allocation

Expand the fund allocation section to distribute your investments across the G, F, C, S, I, and L Funds. The calculator blends their historical return rates into a weighted average and uses that for projections. For long-term growth, many advisors recommend a C/S/I-heavy mix. Lifecycle (L) Funds automatically balance risk for you.

Review Results and Export

View your projected balance, BRS match totals, investment growth breakdown, 4% rule income estimate, and year-by-year chart. Enable the BRS vs Legacy High-3 comparison to see estimated pension values side by side. Export your full year-by-year projection as a CSV file for budget planning or financial review.

Frequently Asked Questions

What is the 2026 TSP contribution limit?

For 2026, the standard elective deferral limit is $24,500. Service members and federal employees who are age 50 or older (but not 60–63) can contribute an additional $8,000 catch-up contribution for a total of $32,500. Those between ages 60 and 63 benefit from the SECURE Act 2.0 super catch-up of $11,250 instead of $8,000, allowing $35,750 total. Combat zone deployments allow contributions up to the annual additions limit of $72,000, which bypasses the standard $24,500 elective deferral cap. All limits reset on January 1 of each year.

How does BRS matching work exactly?

The Blended Retirement System provides three layers of TSP contributions: First, a 1% automatic contribution of your basic pay starting after 60 days of service — you receive this even if you contribute nothing yourself. Second, a dollar-for-dollar match on the first 3% of basic pay you contribute. Third, a 50-cent match on each dollar of the next 2% you contribute. Combined, if you contribute 5% of your basic pay, the government contributes another 5%, for a total of 10% of basic pay going into your TSP each pay period. The 1% automatic contribution vests after 2 years; matching contributions vest immediately on the first day of matching eligibility (24 months of service).

Why might I lose BRS matching if I max out TSP too early?

BRS agency matching is paid each pay period — not as a lump sum at year end. If you contribute too much early in the year and hit the $24,500 limit in, say, October, you stop making contributions for November and December. Since the match is paid only when you contribute, you receive no matching for those final months. To avoid this, spread contributions evenly across all 12 months: $24,500 ÷ 12 ≈ $2,042/month. Our calculator displays this exact recommended monthly amount so you can preserve every dollar of matching through December.

What is the difference between Traditional and Roth TSP?

Traditional TSP contributions are pre-tax — they reduce your taxable income today, and you pay income tax when you withdraw in retirement. This is best if you expect your tax rate in retirement to be lower than today. Roth TSP contributions are after-tax — you pay tax now, but qualified withdrawals (account open 5+ years, age 59½+) are completely tax-free, including all growth. This is best if you expect to be in a higher tax bracket in retirement. Importantly, all government and agency matching contributions always go into a Traditional TSP account regardless of your Roth election. In a combat zone, Roth contributions from tax-exempt combat pay achieve a triple tax benefit: no tax on income, growth, or withdrawal.

Which TSP fund should I choose?

The answer depends on your time horizon and risk tolerance. The C Fund (S&P 500 index, ~10.4% historical return) and S Fund (small-cap, ~9.6%) have generated the highest long-term returns but with more volatility. The I Fund (international stocks, ~6.2%) provides diversification. The G Fund (Treasury securities, ~4.1%) offers capital preservation with no credit or market risk — ideal near retirement. The F Fund (bond market, ~5.8%) sits between stocks and G Fund in risk/return. Lifecycle (L) Funds automatically shift from stock-heavy to conservative as you approach your target retirement year and are a sensible default. Many advisors suggest C/S/I-heavy allocations for those with 15+ years to retirement.

Should I choose BRS or stay in the Legacy High-3 system?

Service members who entered before January 1, 2018 and were eligible to opt into BRS during the 2018–2020 opt-in window had to weigh the choice: Legacy High-3 provides a higher pension multiplier (2.5% vs. BRS's 2%) but no TSP employer match. BRS provides a lower pension but adds the TSP match and continuation pay. For those who serve fewer than 20 years (the vast majority), BRS is almost always superior because Legacy High-3 pays nothing at separation before 20 years, while BRS provides vested TSP assets. For career 20-year service members, Legacy can result in a higher lifetime pension — but the TSP match often closes the gap. Use our comparison mode to estimate both side by side.