TSP Growth Calculator

The IRS sets annual limits on how much you can contribute to defined contribution plans, including the TSP. For 2026, the baseline elective deferral limit is $23,500. If you are aged 50 or older, you are eligible for catch-up contributions. Additionally, under SECURE 2.0 rules, employees aged 60 to 63 benefit from a higher "super catch-up" limit.

It is important to understand that the agency automatic (1%) and matching contributions do not count toward your $23,500 elective deferral limit. They only count toward the broader $70,000 total annual addition limit. If you are trying to maximize your TSP, you must spread your contributions across all pay periods. If you hit the $23,500 limit too early in the year, your personal contributions will stop, and you will miss out on the agency matching contributions for the remaining pay periods.

If you are covered under FERS or the military's Blended Retirement System (BRS), your agency provides automatic and matching contributions. Maximizing this match is the most critical step in growing your TSP. If you contribute less than 5% of your basic pay, you are leaving part of your compensation on the table.

Here is exactly how the 5% agency match breaks down:

The agency provides a dollar-for-dollar match on the first 3% of your pay, and 50 cents on the dollar for the next 2%. To get the full 5% from your agency, you must contribute at least 5% yourself.

For example, if your basic pay is $80,000 and you contribute 5% ($4,000), your agency will contribute an additional 5% ($4,000) to your account. That instantly doubles your investment before market returns even factor in. Federal employees planning their exit strategy often use the best month to retire calculator to time their final contributions and maximize their leave payouts alongside their final TSP match.

Your TSP contributions are calculated as a percentage of your basic pay. Because federal employees typically receive annual cost-of-living adjustments (COLAs) and periodic step increases, your basic pay will rise over your career.

When your salary increases, the dollar amount of your TSP contributions increases automatically, even if you leave your contribution percentage the same. For instance, a 5% contribution on a $60,000 salary is $3,000. If your salary grows to $90,000 over a decade, that same 5% contribution becomes $4,500—and the agency match increases proportionally.

The calculator includes an "Annual Salary Growth Rate" input to account for this. A conservative estimate is 1.5% to 2.5%, representing average federal pay raises. If you expect a major promotion or are moving rapidly up the General Schedule (GS) scale, you might use a slightly higher rate. Accounting for wage growth ensures you get a realistic retirement projection rather than a flat, stagnant estimate.

To project your TSP balance accurately, you need to input your current financial snapshot. Start with your current age, planned retirement age, and current salary.

Next, input your current TSP balance and your employee contribution rate. The calculator allows you to enter your contribution as a percentage of your salary. If you plan to make catch-up contributions after age 50, toggle that option to "1" (Yes).

Finally, select an expected annual return rate. Your return rate should reflect the specific TSP funds you are invested in. You can also adjust the inflation rate and safe withdrawal rate in the advanced settings. The safe withdrawal rate helps estimate your monthly retirement income—many retirees use the 4% rule as a baseline, which you can explore further in our retirement spend down calculator.

The calculator builds your projection year by year. It calculates your salary, limits your contributions based on IRS maximums, calculates the exact agency match, and applies investment growth to your total balance.

Here is the formula used to determine your agency matching contribution (assuming standard FERS/BRS rules):

Employer Match = (Tier 1 Match) + (Tier 2 Match)

Where:

• Tier 1 Match = 100% of your contribution up to 3% of your salary.
• Tier 2 Match = 50% of your contribution between 3% and 5% of your salary.

To find your total contributions for the year, the calculator applies this formula:

Total Annual Contributions = Employee Deferral + (Salary × 1% Automatic) + Employer Match

Where:

• Employee Deferral = Your chosen percentage of salary, capped at the $23,500 IRS limit (or higher if catch-up eligible).
• 1% Automatic = The agency automatic contribution given to all eligible employees regardless of personal contribution.
• Employer Match = The calculated match based on your deferral rate.

Finally, your end-of-year balance is calculated by applying your expected return rate to your total funds:

End Balance = (Start Balance + Total Annual Contributions) × (1 + Annual Return Rate)

Where:

• Start Balance = Your account value at the beginning of the year.
• Total Annual Contributions = The sum of your deferrals and agency money.
• Annual Return Rate = Your expected investment growth percentage.

By running this math sequentially for every year until your retirement age, the calculator shows how compound interest does the heavy lifting in the later stages of your career.

Your "Annual Investment Return Rate" input drastically changes your final result. The TSP offers five core individual funds and a series of Lifecycle (L) Funds. Your expected return should align with your specific asset allocation:

• G Fund (Government Securities): The G Fund guarantees principal protection. It historically returns slightly above inflation (around 3% to 4%). It is extremely safe but offers minimal real growth over decades.
• F Fund (Fixed Income): This fund tracks a broad U.S. bond index. It offers moderate returns (typically 4% to 5%) with low volatility, serving as a stabilizer for your portfolio.
• C Fund (Common Stock): The C Fund tracks the S&P 500 index, representing large U.S. companies. It historically averages 9% to 10% annually over long periods but comes with higher market volatility.
• S Fund (Small Cap): The S Fund tracks small and medium-sized U.S. companies. It offers high growth potential, often outpacing the C Fund during bull markets, but carries higher risk.
• I Fund (International): This fund tracks international stock markets, providing global diversification outside the United States.
• L Funds (Lifecycle): These are target-date funds that automatically shift your money from aggressive investments (C, S, and I funds) to conservative investments (G and F funds) as you approach retirement.

If you are 20 years away from retirement and fully invested in the L 2045 or L 2050 funds, an expected return of 6% to 8% is generally reasonable for planning purposes. If you are entirely in the G Fund, setting your return rate higher than 4% will result in an artificially inflated projection.

While this calculator projects your gross balance, it is important to consider how taxes will affect your usable income in retirement. The TSP allows you to make both Traditional (pre-tax) and Roth (after-tax) contributions.

Traditional TSP contributions lower your taxable income today. Your investments grow tax-deferred, but you must pay ordinary income tax on every dollar you withdraw in retirement. Furthermore, Traditional balances are subject to Required Minimum Distributions (RMDs) starting at age 73 (rising to 75 in 2033). Understanding required minimum distributions explained and learning how to reduce taxes on required minimum distributions is a vital part of late-career planning.

Roth TSP contributions are made with money that has already been taxed. You get no upfront tax break, but your money grows tax-free, and qualified withdrawals in retirement are completely tax-free. As of 2024, Roth TSP balances are no longer subject to RMDs during your lifetime, aligning the rules with standard Roth IRAs.

Note that regardless of whether you choose Traditional or Roth for your own contributions, your agency's automatic 1% and matching contributions are always deposited into your Traditional TSP balance.

When projecting your TSP growth, it is equally important to plan how you will access that money in retirement. The TSP modernization act significantly expanded your withdrawal options, giving you more flexibility than federal retirees had in the past.

You can take single withdrawals, set up installment payments based on a fixed dollar amount, or set up payments based on life expectancy. If you choose installment payments, you can change the amount or frequency at any time. You also have the option to purchase a life annuity through the TSP's outside vendor, which guarantees a monthly income stream for the rest of your life.

When modeling your future income, the "Safe Withdrawal Rate" input helps estimate how much you can sustainably pull from your account each year. A 4% withdrawal rate is a common benchmark, meaning if your projected balance is $1,000,000, you might plan to withdraw $40,000 in your first year of retirement. However, because federal retirees also receive a pension and Social Security, many find they can use a lower withdrawal rate, which you can test in our safe withdrawal rate calculator.

One of the most overlooked factors in long-term retirement planning is inflation. A projected TSP balance of $1.5 million might sound like a fortune today, but 25 years from now, that money will not have the same purchasing power.

This calculator includes an advanced setting for the inflation rate. By factoring in inflation (historically averaging around 2.5% to 3%), the calculator can show you the "real" value of your future balance. For example, if your nominal balance is projected to be $1,500,000 at retirement, its purchasing power in today's dollars might only be $800,000. This stark reality highlights why investing in growth-oriented funds is critical for younger employees; relying solely on the G Fund often means your returns will barely keep pace with inflation, making it harder to reach your true retirement number.