FERS Annuity Calculator

Estimate your Federal Employees Retirement System basic annuity, the cost of each survivor benefit election, and the FERS Supplement bridge payment if you retire before 62. Enter your numbers below — the calculation takes three seconds.

What each input means

High-3 average salary

The highest average basic pay over any 3 consecutive years — almost always your final 3 years. Includes base pay only; excludes overtime, awards, and locality pay above base. If you had a promotion in the last few years, your high-3 could be lower than your current salary.

Years of FERS creditable service

Total years including part-time periods (prorated), military service you've bought back, and any unused sick leave (see below). Does not count LWOP in excess of 6 months per year unless it's OWCP.

Unused sick leave

At retirement, OPM converts your remaining sick leave balance to additional creditable service — months and days are added directly to your years of service for annuity calculation purposes. A full year of sick leave (2,087 hours) equals approximately one additional year of service. This calculator uses months for simplicity (1 month = 1/12 year).²

Survivor benefit election

FERS offers three tiers: life-only (no survivor benefit, maximum monthly check), partial (25% of your unreduced annuity to your spouse after your death, costs 5% reduction to your annuity), and full (50% of your unreduced annuity to your spouse, costs 10% reduction). Once annuity payments begin, this election is irrevocable unless your spouse dies or you divorce.³

About the FERS Supplement

If you retire before 62, FERS provides a bridge payment called the FERS Annuity Supplement — it approximates the Social Security benefit you earned under FERS service. It starts when your annuity begins and stops at exactly age 62 (regardless of when you claim actual Social Security).

Supplement formula: (Years of FERS Service ÷ 40) × Your Estimated Full-Career SS Benefit at 62.⁴ As a rough proxy, this calculator uses your SSA.gov projected benefit at 62 — OPM's actual computation uses a projected full-career benefit that may differ slightly.

The 1.1% multiplier: the math behind waiting until 62

The difference between retiring at 61 and 62 with 20+ years of service looks small in percentage terms but adds up significantly over a 20-30 year retirement.

Example: GS-13 Step 10, high-3 of $128,000, retiring with 28 years of service:

• At 61 (1.0% multiplier): $128,000 × 1.0% × 28 = $35,840/year ($2,987/month)
• At 62 (1.1% multiplier): $128,000 × 1.1% × 28 = $39,424/year ($3,285/month)
• Difference: $3,584/year ($298/month) — permanently, for life
• Value at 20-year horizon: ~$72,000 cumulative (undiscounted)

Whether waiting one year for the 1.1% multiplier is worth it depends on your specific situation — especially if you plan to work elsewhere between 61 and 62, or if health considerations are a factor. A fee-only specialist can model the breakeven for your numbers.

Factors this calculator doesn't include

• COLA. Your FERS annuity is COLA-adjusted using the "diet COLA" formula: if the CPI increase is 2% or less, you get the full CPI; if it's 2-3%, you get 2%; if it exceeds 3%, you get CPI minus 1 percentage point. This meaningfully protects your purchasing power over a 20-30 year retirement — a major advantage over fixed corporate pensions.
• Part-time service proration. Years worked part-time are credited at a prorated rate; the annuity is then calculated and re-prorated. The net effect: part-time service counts, but at less than 1:1 toward the final annuity. OPM's calculation is precise; this calculator assumes full-time equivalence.
• Special category employees. Law enforcement officers, firefighters, air traffic controllers, and Capitol Police accrue benefits differently (1.7% per year for the first 20 years in some cases). This calculator uses the standard FERS multiplier only.
• CSRS offset or CSRS component. Employees with CSRS service before 1987 who transferred to FERS have a mixed benefit calculation. This calculator is for pure FERS only.
• TSP. Your Thrift Savings Plan balance is separate from this annuity. At retirement you choose whether to keep it in TSP, roll it to an IRA, or take distributions. The Lump Sum vs Annuity Calculator and FERS Retirement Guide cover the TSP decision in detail.