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TSP Loan Calculator

Work out your TSP loan limit and biweekly payroll payment, with the rules for general purpose and residential loans.

Updated November 4, 2026. Free, no sign-up; everything runs in your browser and nothing you type is stored.

TSP loan calculator

Your own contributions + earnings ($)Vested account balance ($)Outstanding TSP loan balance now ($)Highest TSP loan balance in last 12 months ($)Amount you want ($)Loan typeRepayment term (years)G Fund rate (%)

Biweekly payment

–

–Most you can borrow

–Total interest (paid back into your account)

–Loan fee

TSP loan rules

Federal employees and members of the uniformed services can borrow from their own Thrift Savings Plan contributions and earnings and repay by payroll deduction (TSP loan booklet):

Minimum: $1,000.
Maximum: the smallest of (1) your own contributions and their earnings (not agency contributions), (2) the greater of $10,000 or 50% of your vested balance, minus any outstanding loan, and (3) $50,000 minus your highest outstanding loan balance in the last 12 months.
Types: general purpose, repaid over 1-5 years, $50 fee; residential (to buy or build a primary home, with documents), 1-15 years, $100 fee.
Interest: the G Fund rate when you apply, fixed for the loan. Interest goes back into your own account.

Worked example

Borrowing $20,000 for 5 years at a 4.25% G Fund rate costs $170.90 every two weeks, 130 payments, with $2,216 of interest paid to yourself.

The real costs

Borrowed money is out of the market, so you lose any return above the G Fund rate, and repayments are made with after-tax pay that is taxed again when withdrawn in retirement. If you leave federal service and don't repay by the deadline in the TSP's notice, the unpaid balance becomes a taxable distribution, with the 10% early withdrawal tax if you're under 59½. Plan retirement with the TSP retirement calculator and FERS retirement calculator.

Common questions

How much can I borrow from my TSP?

The smallest of your own contributions and earnings, 50% of your vested balance (or $10,000) less loans, and $50,000 less your highest loan balance in 12 months.

What is the TSP loan interest rate?

The G Fund rate when you apply, fixed for the life of the loan.

How long can a TSP loan last?

1-5 years for general purpose, up to 15 years for residential.

Sources

More retirement calculators: Social Security Quick Calculator · Solo 401k Calculator 2026 vs SEP IRA & SIMPLE IRA · 401k Rollover to IRA · 403b Plan

General information, not financial, tax or legal advice. Check important numbers with the official source before acting on them.