TSP Calculator
Estimate TSP growth with a built-in standard automatic 1% plus matching schedule through 5% of basic pay. The projection models eligible catch-up contributions and spreads employee and agency cash flows across each year.
How to use this calculator
Enter current balance, annual basic pay, employee contribution rate, age, prior-year FICA wages from the TSP sponsor, salary and future-limit growth, annual return, and years.
Review TSP contribution limits, Blended Retirement System or FERS rules, matching eligibility, vesting, fund allocation, tax treatment, and current fees.
Read projected balance, regular employee contributions, age-based contributions allocated to the required Roth bucket when applicable, agency contributions, and investment growth.
Formula
Regular employee deferral is capped at the modeled $24,500 limit, with eligible age catch-up separate. Agency contributions use automatic 1%, dollar-for-dollar on the first 3%, and 50 cents per dollar on the next 2%.
Worked example
On $80,000 basic pay, a 5% contribution equals $4,000 annually before pay-period timing and the applicable agency matching formula.
Assumptions and limits
- TSP Roth catch-up is modeled as available. For 2026, prior-year FICA wages from the sponsor above $150,000 route age-based catch-up contributions to Roth; actual payroll and eligibility records control.
- TSP Calculator treats the entered values as estimates and does not infer missing project, account, or personal details.
- Calculations retain working precision except where the cited method requires an intermediate rounding step; displayed values are then formatted separately. Source rules and dated rates must be rechecked when they change.
Sources
- Thrift Savings Plan: How TSP Fits Into Your RetirementTSP contributions, agency matching, and participant rules. Reviewed 2026-08-14.
- Internal Revenue Service: Retirement Topics: Catch-Up Contributions2026 age-based catch-up limits and the prior-year wage test for required Roth catch-up treatment. Reviewed 2026-08-14.
- U.S. Securities and Exchange Commission: Compound Interest CalculatorCompound-growth inputs and future-value concepts. Reviewed 2026-08-14.
- Thrift Savings Plan: How agency and service matching contributions workOfficial formula or method source used by this calculator. Reviewed 2026-08-14.
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Verification
How this calculator is checked
Trust comes from reproducible evidence, not model confidence. You can inspect the formula, assumptions, worked example, and cited sources on this page.
- Versioned calculationFormula logic is kept separate from the interface and covered by automated registry and behavior checks.
- Cited evidenceSources linked for independent checking: 4.
- Transparent AI useAI may assist drafting or adversarial review. Agreement between models is not proof, and no human expert review is claimed unless a named reviewer is shown.
Frequently asked questions
How does the TSP Calculator work?
Regular employee deferral is capped at the modeled $24,500 limit, with eligible age catch-up separate. Agency contributions use automatic 1%, dollar-for-dollar on the first 3%, and 50 cents per dollar on the next 2%.
What information should I enter in the TSP Calculator?
Enter current balance, annual basic pay, employee contribution rate, age, prior-year FICA wages from the TSP sponsor, salary and future-limit growth, annual return, and years, then verify TSP contribution limits, Blended Retirement System or FERS rules, matching eligibility, vesting, fund allocation, tax treatment, and current fees.
What should I verify before using this TSP Calculator result?
TSP Roth catch-up is modeled as available. For 2026, prior-year FICA wages from the sponsor above $150,000 route age-based catch-up contributions to Roth; actual payroll and eligibility records control.
Last updated 2026-08-25 · 2026-monthly-retirement-projection-v4 · content-2026-08-14 · Published by YunFanLabs