Inputs you will enter
- Current TSP balanceFrom your latest TSP statement.
- Basic payAnnual. Include locality pay.
- Your contributionPercent of pay, split between traditional and Roth if you like.
- Years until you stop contributingYour planned retirement year.
- Return rateYour assumption, as a yearly percentage. No default is presented as typical.
- Yearly pay changeOptional, your assumption.
How we compute it
Each pay period, we add your contribution and your agency's: 1 percent automatic, plus 100 percent of the first 3 percent you put in and 50 percent of the next 2 percent (TSP, retrieved 2026-07-05). We cap your contributions at the IRS limit in effect for the year shown.
For the illustration, we apply your return rate evenly each year. Real fund returns move up and down, sometimes sharply, and can be negative. The steady line is arithmetic, not a forecast. For context, our TSP share price history page lists each fund's past annual returns from official TSP prices; those are historical facts as of their date, not a guide to the future.
A worked example
You earn $80,000 and contribute 5 percent, $4,000 a year. Your agency adds 1 percent automatic ($800) plus the 4 percent match ($3,200), so $8,000 goes in each year. If you contributed 3 percent instead, your agency would add $3,200 in total, and you would miss $800 a year of match. Educational estimate on the assumptions shown.
What to do with your numbers
Read TSP basics, compare the TSP funds and their risks, and learn your withdrawal options before you separate.
Deciding how to draw down your TSP alongside your pension is one of the bigger choices you will make.
FFEBA is an education organization. If you want someone to look at your own numbers, we can match you with a Federal Retirement Consultant (FRC), a professional trained on federal benefits. The FRC designation is listed with FINRA. The first review is free, nothing is booked until you choose a time, and you are never obligated to work with anyone we introduce. Get matched with an FRC.
Questions about this calculator
How much does my agency put in my TSP?
FERS employees get an automatic 1 percent of basic pay, plus a match: dollar for dollar on the first 3 percent you contribute and 50 cents on the dollar on the next 2 percent. Contributing 5 percent captures the full 5 percent from your agency (TSP, retrieved 2026-07-05).
What return rate should I use?
That is your call, and it is an assumption, not a prediction. You can look at each fund's historical annual returns on our TSP share price page for context, but past returns do not tell you future ones. Try a low, middle and high rate to see a range.
Does this calculator include the Roth TSP?
Yes. You can split your contribution between traditional and Roth. Agency contributions always go to the traditional balance. The tool does not estimate taxes on withdrawals.
What is the TSP contribution limit?
The IRS sets the yearly elective deferral limit and the catch-up limit. The tool prefills the current figures with their as-of date and warns you if your inputs exceed them.
Can this tell me how much I can withdraw in retirement?
It shows a simple illustration of a fixed monthly withdrawal at the rate you choose. It does not model taxes, required minimum distributions or market swings. The TSP withdrawals guide explains your actual options.
Reviewed by the FFEBA education team. Last reviewed October 2026.
Sources
- Thrift Savings Plan, making contributions, retrieved 2026-07-05
- Thrift Savings Plan, daily share price history (historical returns), retrieved 2026-09-10
Every government figure on this page carries its source and retrieval date. Worked examples are educational estimates on the assumptions shown, not a projection of any person's benefit. FFEBA is an education organization, not a financial advisor.
