TSP Calculator

Begin by entering your current financial and personal details. In the "Salary & Contributions" section, provide your annual base pay and the percentage you contribute to your TSP with each paycheck. This is used to calculate both your contributions and the agency match.

Next, in "Personal Details," enter your current age and planned retirement age to set the timeline for your savings growth. Add your current TSP balance and an expected annual investment return. A long-term average of 7% is a common estimate, but you can adjust this based on your risk tolerance and TSP fund allocation.

Under "Service Type," specify whether you are a FERS civilian employee or a military BRS member. The calculator uses the same matching formula for both, but this input helps provide relevant context in the results.

For a more detailed projection, open the "Advanced Settings." Here you can specify what percentage of your contributions go to the Roth TSP, whether you're eligible for catch-up contributions (age 50+), and your expected annual pay raise. Including a pay raise provides a more realistic long-term projection as your salary and contributions grow over time.

Annual Salary

This is your annual base pay before any deductions. The calculator uses this figure to determine the dollar amount of your contributions (based on your contribution rate) and to calculate the government's matching contribution.

Contribution Rate

Enter the percentage of your salary you contribute from each paycheck. To receive the full 5% government match, you must contribute at least 5% of your own salary. This is one of the most powerful inputs for growing your TSP balance.

Current Age & Retirement Age

Your current age and planned retirement age define your investment horizon. The more years you have until retirement, the more time your contributions, agency match, and investment earnings have to compound. Use our retirement age calculator to see how different timelines affect your outcome.

Current TSP Balance

This is the total amount you currently have saved in your TSP account. This starting principal is a critical component of the long-term growth projection.

Expected Annual Return

This is the average annual rate of return you expect your TSP investments to generate. This is an estimate, not a guarantee. Your actual return will depend on your allocation across the G, F, C, S, I, and L funds and overall market performance.

Service Type (FERS vs. BRS)

Select whether you are a federal civilian employee under FERS or a military member under the Blended Retirement System (BRS). Both systems currently use the same matching contribution formula: an automatic 1% agency contribution, plus a dollar-for-dollar match on your first 3% of contributions and a 50-cent-per-dollar match on the next 2%.

Roth TSP Portion

In the advanced settings, you can specify the percentage of your contributions that you direct to the Roth TSP. Roth contributions are made with after-tax dollars, meaning qualified withdrawals in retirement are tax-free. Agency matching funds are always deposited into your traditional TSP balance, regardless of your election.

Catch-Up Eligible (Age 50+)

If you are age 50 or older, you are eligible to make additional "catch-up" contributions above the standard elective deferral limit. For 2026, this allows for an extra $7,500 in contributions. Enable this option if you are 50 or older to see its impact.

Annual Pay Raise

This is your expected average annual salary increase. This can come from regular step increases, promotions, or cost-of-living adjustments (COLAs). Including a realistic pay raise makes the projection more accurate, as your contributions and match will increase as your salary grows.

This calculator uses a year-by-year projection to model the growth of your TSP account from your current age to your planned retirement age.

The process starts with your current TSP balance. For each year in the projection, the calculator first determines your salary, adjusting it upwards based on the "Annual Pay Raise" input. It then calculates your annual employee contribution based on your salary and contribution rate, ensuring it does not exceed the 2026 IRS limit of $23,500 (plus an additional $7,500 if you are eligible for catch-up contributions).

Next, it calculates the agency/service matching contribution based on the 5% formula. It then adds your contribution and the agency match to the starting balance for that year. Finally, it applies the "Expected Annual Return" to the new total to calculate investment growth for the year. This final number becomes the starting balance for the next year, and the process repeats until you reach retirement age.

The TSP Contribution Score is a simple metric based on your contribution rate. A rate of 5% or higher earns a high score because you are capturing the full government match. A rate below 5% results in a lower score, highlighting the "free money" you may be leaving on the table.

The projection is built iteratively, year by year. Here are the core formulas used in each step.

Agency Match Formula

The total agency match is the sum of three parts, based on a contribution rate of at least 5%.

automatic_1_percent = annual_salary * 0.01

dollar_for_dollar_match = min(employee_contribution_rate, 0.03) * annual_salary

fifty_cent_match = max(0, min(employee_contribution_rate, 0.05) - 0.03) * annual_salary * 0.5

total_agency_match = automatic_1_percent + dollar_for_dollar_match + fifty_cent_match

Annual Contribution Formula

Your contribution is calculated and capped by IRS limits.

standard_limit = 23500
catch_up_limit = 7500 (if age >= 50 and eligible)
total_limit = standard_limit + catch_up_limit

employee_contribution = min(annual_salary * (contribution_rate / 100), total_limit)

Year-Over-Year Growth Formula

For each year of the projection, the new balance is calculated.

investment_growth = (current_balance + employee_contribution + total_agency_match) * (expected_return / 100)

end_of_year_balance = current_balance + employee_contribution + total_agency_match + investment_growth

The government matching contribution is one of the most valuable benefits of the Thrift Savings Plan and a cornerstone of the FERS and BRS retirement systems. Failing to take full advantage of it is like turning down a 100% return on your investment.

The match is broken down into two components:

1. Agency/Service Automatic 1% Contribution: Your agency or service automatically contributes an amount equal to 1% of your basic pay to your TSP account each pay period. You receive this even if you contribute nothing.
2. Agency/Service Matching Contributions: This part depends on how much you contribute.
   • The first 3% you contribute is matched dollar-for-dollar.
   • The next 2% you contribute is matched at 50 cents on the dollar.

To get the maximum match, you must contribute at least 5% of your basic pay. If you do, the total government contribution will be 5% (1% automatic + 4% matching), effectively doubling your savings rate on that first 5%. Use the TSP match calculator for a more detailed breakdown.

The TSP offers both Traditional (pre-tax) and Roth (after-tax) contribution options, giving you flexibility in how you manage your future tax liability.

Traditional TSP:

• Contributions: Made with pre-tax dollars, which reduces your current taxable income. If you earn $90,000 and contribute $10,000 to your Traditional TSP, you are only taxed on $80,000 of income for that year.
• Growth: Your investments grow tax-deferred.
• Withdrawals: Withdrawals in retirement are taxed as ordinary income.

The Traditional TSP is often favored by those who believe they will be in a lower tax bracket in retirement than they are today.

Roth TSP:

• Contributions: Made with after-tax dollars. You get no immediate tax deduction.
• Growth: Your investments grow completely tax-free.
• Withdrawals: Qualified withdrawals in retirement (generally after age 59½ and five years of contributions) are 100% tax-free.

The Roth TSP is often a good choice for those who expect to be in the same or a higher tax bracket in retirement, or for those who value the certainty of tax-free income. You can learn more about the differences in our guide to Roth vs. Traditional IRAs, as the principles are very similar.

It's important to note that all agency matching contributions are made to your Traditional TSP balance, even if you contribute 100% to the Roth TSP. This means most federal employees will have both Traditional and Roth balances at retirement.

For 2026, the IRS elective deferral limit for employee contributions to the TSP (and similar plans like the 401(k) and 403(b)) is $23,500.

If you are age 50 or over, you can also make "catch-up" contributions. The catch-up contribution limit for 2026 is $7,500. This means an eligible employee can contribute a total of up to $31,000 ($23,500 + $7,500).

These limits apply only to your own contributions. They do not include the agency's automatic 1% or matching contributions. The total amount that can be contributed to your account from all sources (employee, agency automatic, and agency matching) is capped at $70,000 for 2026, though most federal employees will not approach this limit.

TSP Contribution Score: This gauge provides an instant assessment of your contribution strategy. A score above 80 indicates you are contributing at least 5% and capturing the full government match. A lower score is a clear signal to increase your contribution rate to avoid leaving free money on the table.

Projected Balance at Retirement: This is the calculator's estimate of your total TSP account value at your specified retirement age. It is the sum of your starting balance, all your future contributions, all agency contributions, and all investment growth.

Balance Composition Chart: This donut chart shows what portion of your final balance comes from four sources: your starting balance, your own contributions, the agency match, and investment growth. For long-term employees, investment growth often becomes the largest single component, demonstrating the power of compounding.

TSP Growth Projection Chart: This area chart visualizes your TSP balance growing year by year. It provides a clear picture of how consistent saving and investment returns can build substantial wealth over a career.

Insights Panel: This section provides dynamic feedback based on your specific inputs. It will confirm if you're getting the full match, warn you if you're missing out, highlight the availability of catch-up contributions, and explain the matching structure for your service type.

If your projected balance is lower than you'd like, consider these strategies:

1. Contribute at Least 5%: This is the single most important step. If you are contributing less than 5%, you are turning down free money from the government. Make it your top priority to reach this threshold.
2. Increase Your Contribution Rate: Try to increase your contribution percentage by 1% each year, or with every pay raise. Small, consistent increases can lead to a significantly larger balance over time.
3. Utilize Catch-Up Contributions: If you are age 50 or older, take full advantage of the catch-up contribution limit. This can supercharge your savings in your final working years.
4. Review Your Fund Allocation: While this calculator uses a single return rate, your real-world results depend on your investment mix. Periodically review your allocation in the G, F, C, S, I, and Lifecycle (L) funds to ensure it aligns with your risk tolerance and time horizon.
5. Work a Little Longer: Delaying retirement by even a few years can have a dramatic impact. It gives your investments more time to grow and shortens the period you'll need to draw down your savings. Use the retirement age calculator to model different scenarios.

1. Not Contributing 5%: This is the most common and costly mistake. Always contribute enough to get the full 5% government match.
2. "Set It and Forget It" with Contributions: Many employees set their contribution rate when they're hired and never increase it. As your salary grows, your savings rate should too.
3. Being Too Conservative Too Early: While the G Fund offers safety of principal, keeping your entire balance there for a 30-year career can severely limit your growth potential due to inflation.
4. Ignoring Catch-Up Contributions: Many employees who become eligible for catch-up contributions at age 50 forget to increase their contribution amount to take advantage of the higher limit.
5. Not Having a Withdrawal Plan: Before you retire, it's crucial to understand the TSP withdrawal options and how they will be taxed. Planning for tax-efficient withdrawals can make your money last longer.