Calculating your FERS pension doesn’t have to be mysterious. The Office of Personnel Management (OPM) uses a simple, consistent formula — and once you understand each piece, you can estimate your own pension in a few minutes.
This guide walks you through every step, with real examples.
The FERS Pension Formula
Annual Pension = High-3 Average Salary × Years of Creditable Service × Multiplier
That’s it. Three numbers multiplied together. Let’s break each one down.
Step 1: Find Your High-3 Average Salary
Your High-3 is the average of your three consecutive highest-earning years of basic federal pay. Key points:
- “Basic pay” means your base salary — it does NOT include overtime, bonuses, or locality pay in some calculations (though locality pay is typically included in GS base pay)
- The three years must be consecutive, but they don’t have to be your final three years
- If you had a significant pay increase (such as a promotion) more than three years before retirement, those earlier years might actually be your High-3
How to calculate your High-3:
- List your basic pay for each of the last 5–6 years
- Find the three consecutive years with the highest total
- Average those three years
Example:
| Year | Salary |
|---|---|
| 2020 | $82,000 |
| 2021 | $86,000 |
| 2022 | $91,000 |
| 2023 | $95,000 |
| 2024 | $99,000 |
Best three consecutive years: 2022–2024 → High-3 = ($91,000 + $95,000 + $99,000) ÷ 3 = $95,000
Step 2: Count Your Years of Creditable Service
Your “creditable service” includes:
- All years as a federal civilian employee under FERS
- Any qualifying military service for which you have paid a deposit
- Unused sick leave (see below)
The Sick Leave Bonus
Under FERS, unused sick leave at retirement is converted into additional service credit. The conversion rate is approximately:
- 174 hours = 1 additional month of service
- 2,087 hours = 1 full year of service credit
Example: You retire with 1,044 hours of unused sick leave. That’s 1,044 ÷ 174 ≈ 6 months of additional service credit added to your total.
This is essentially free pension money — every unused sick leave hour has a dollar value in your retirement.
Step 3: Apply the Correct Multiplier
The multiplier is either 1% or 1.1%:
| Retirement Age | Years of Service | Multiplier |
|---|---|---|
| Under 62 | Any | 1.0% |
| 62 or older | Under 20 years | 1.0% |
| 62 or older | 20+ years | 1.1% |
The 1.1% multiplier is one of the most powerful incentives in federal retirement planning. If you can arrange to retire at 62 with 20+ years, you receive 10% more pension — for life.
Step 4: Run the Calculation
Example 1 — Standard retirement:
- High-3: $90,000
- Years of service: 22 years (plus 6 months from sick leave = 22.5 years)
- Retirement age: 57
- Multiplier: 1% (under 62)
- Annual pension: $90,000 × 22.5 × 0.01 = $20,250 ($1,688/month)
Example 2 — The 1.1% bonus:
- High-3: $95,000
- Years of service: 25 years
- Retirement age: 62
- Multiplier: 1.1% (62+ with 20+ years)
- Annual pension: $95,000 × 25 × 0.011 = $26,125 ($2,177/month)
Example 3 — Late career maximizer:
- High-3: $115,000 (GS-14)
- Years of service: 30 years
- Retirement age: 63
- Multiplier: 1.1%
- Annual pension: $115,000 × 30 × 0.011 = $37,950 ($3,163/month)
Common Calculation Mistakes to Avoid
- Using gross pay instead of basic pay. Overtime and bonuses generally don’t count toward your High-3.
- Forgetting sick leave credit. Many employees lose thousands of dollars by not accounting for their sick leave balance.
- Not checking if you qualify for 1.1%. Even a 63-year-old with 19 years of service doesn’t get 1.1% — you need 20+ years.
- Assuming your last 3 years are automatically your High-3. If you had a higher-paying position or locality area earlier in your career, check those years too.
What About COLA?
Once you retire, your FERS pension receives annual Cost-of-Living Adjustments (COLAs):
- If you’re under 62 when you retire, you receive NO COLA until you turn 62
- At 62 and older, FERS retirees receive: CPI − 1% (if CPI ≤ 2%) or CPI minus 1 percentage point (if CPI > 2%)
- CSRS retirees receive full CPI — a key advantage of the older system
Try the Calculator
Don’t want to do the math manually? Use our FERS Pension Calculator — enter your High-3, years of service, and retirement age, and get your instant estimate including sick leave credit, eligibility check, and FERS Supplement eligibility.