TSP Loan Calculator
Estimate the payment on a TSP general-purpose or residential loan, see total interest — which you pay back into your own account at the G Fund rate — and understand the repayment term rules and what happens to an outstanding loan when you separate from federal service.
Works offline — your inputs never leave this device. How that works
The interest goes back into your TSP, but the borrowed balance misses market growth while it's out — that missed growth, not the interest, is the real cost. If you separate from service with a balance outstanding, TSP.gov's post-separation rules apply (repay or the balance becomes a taxable distribution).
Verified 2026-07-30 against IRS Notice 2025-67 (2026 retirement plan limits) + TSP.gov contribution pages (effective 2026-01-01)
Estimate only — not legal, financial, or benefits advice. Only TSP can determine your actual benefit.
Official source: TSP.gov — loan basics ↗
🎓 Understand this tool
What it is
A payment estimator for TSP general-purpose and residential loans, showing the per-paycheck payment, total interest (which goes back into your own account), and the rules that apply while the loan is out.
How it works
TSP loans amortize at the G Fund rate in effect when the loan is issued — general-purpose loans up to 5 years, residential up to 15. The payment math is standard amortization; the distinctive TSP rules (interest paid to yourself, payroll-deduction repayment, payoff obligations at separation) are annotated alongside the numbers.
Getting the most from it
- Enter the amount you are considering borrowing and a term within the allowed range.
- Enter the current G Fund rate from TSP.gov — the tool links it — rather than guessing.
- Compare the total interest line with the note about missed market growth; the interest is not the real cost.
- Read the separation note before borrowing if you might leave federal service during the term.
Reading your result
The payment figure is per month; your payroll deduction will be per pay period. The "interest back to yourself" line is money moved from your pocket to your TSP, not investment growth — the borrowed balance itself misses whatever the funds return while it is out.
What it can't tell you
It cannot quote your exact loan terms, fees, or eligibility — TSP.gov computes those when you apply — and it does not model taxes if a loan is declared a distribution after separation.
Frequently asked questions
You do. TSP loan interest is paid back into your own TSP account at the G Fund rate in effect when the loan is issued. The real cost of the loan is the market growth your borrowed balance misses while it is out of the fund.
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