CSRS Retirement Calculator: How to Use It
CSRS is one of the most generous defined benefit plans in the country. Understanding the tiered formula is what separates a good retirement estimate from a bad one.
What this calculator does
The CSRS Retirement Calculator applies the Civil Service Retirement System's three-tier formula to your high-3 average salary and years of creditable service. It sorts your retirement into one of three cases: an immediate unreduced annuity (55 with 30 years, 60 with 20, 62 with 5), a discontinued service or VERA annuity reduced 2% for each year under 55, or a deferred annuity that starts at 62. It adds sick leave credit for immediate annuities, applies the 80% cap to service, and shows your monthly and annual gross pension. It doesn't model the CSRS Offset reduction at 62.
CSRS was closed to new employees in 1987 when FERS was created. If you're still under CSRS, you almost certainly have significant tenure and the formula rewards that. At 30 years, the multiplier reaches 56.25%. At 41 years and 11 months, the 80% cap kicks in and additional service no longer increases the benefit.
What each input means
High-3 average salary
The average of your three consecutive highest years of basic pay. Same concept as FERS. Find it on your SF-50 Notification of Personnel Action forms. CSRS basic pay excludes overtime, bonuses, and awards. Locality pay is included (5 U.S.C. 5304(c)(2)).
If your salary has grown significantly over your career, your high-3 will almost always be your three most recent full years before retirement. If you took a reduction in grade, look back further.
Years of creditable service
Civilian federal service counts, as does military service if you made the required deposit. The deposit for post-1956 military service is 7% of military basic pay (5 U.S.C. 8334(j)), versus 3% under FERS. Part-time service is prorated.
Sick leave is not included here as a separate input because the calculator adds it automatically. Enter your years of creditable service, then enter your unused sick leave separately in months (about 174 hours per month).
Unused sick leave
CSRS employees who retire on an immediate annuity get full credit for unused sick leave (5 U.S.C. 8339(m)). It doesn't count toward eligibility, and it doesn't count at all if you leave early for a deferred annuity. OPM converts hours to days to months using a 2,087-hour work-year. Take the hours from your most recent leave and earnings statement and convert them to months. Using all your sick leave before retirement is a common mistake. Every 174 hours is worth about one month of additional service credit.
How the tiered formula works
The three tiers apply sequentially to your total years of service:
- First 5 years: 1.5% per year (maximum 7.5%)
- Years 6 through 10: 1.75% per year (maximum 8.75%)
- Years 11 and beyond: 2.0% per year
At exactly 30 years, you've earned 7.5% plus 8.75% plus 40%, which equals 56.25% of your high-3. A $100,000 high-3 at 30 years produces $56,250 annually. That's $4,688 per month before taxes and any survivor benefit election.
The 80% cap
Federal law caps the service-based CSRS benefit at 80% of your high-3 (5 U.S.C. 8339(f)). You hit that ceiling at 41 years and 11 months of service. Working beyond that point doesn't increase your pension. Unused sick leave is the exception: 8339(m) credits it without regard to the cap, so sick leave can take an immediate annuity past 80%.
CSRS-Offset employees
If you were rehired after a break in service after 1983 and had previous Social Security coverage, you may be CSRS-Offset rather than straight CSRS. The pension formula is the same, but your benefit is reduced by your Social Security benefit attributable to your federal service when you become eligible for Social Security.
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Frequently asked questions
How does the CSRS tiered formula work?
Three multipliers applied in sequence: 1.5% for years 1-5, 1.75% for years 6-10, 2.0% for years 11 and beyond. They accumulate. Thirty years produces a total multiplier of 56.25%. The service-based benefit is capped at 80% of your high-3; sick leave credit can go past it.
Does CSRS count sick leave toward retirement?
Yes, if you retire on an immediate annuity. Unused sick leave converts to additional service, even past the 80% cap, but not toward eligibility or a deferred annuity (5 U.S.C. 8339(m)). About 2,087 hours equals one full year. Use your leave and earnings statement to find the exact balance. Don't use sick leave before retirement just to use it up.
What is the CSRS Social Security situation?
Most CSRS employees didn't pay into Social Security during federal service and don't earn credits for it. If you have Social Security from other jobs, the Windfall Elimination Provision previously reduced SS benefits for CSRS pension recipients, but WEP was repealed in January 2025.
Can CSRS employees contribute to TSP?
Yes, up to the IRS annual limit, but with no agency match. The contribution is voluntary and acts as a supplement to the defined benefit pension. FERS employees get 1% automatic plus up to 4% matching (5 U.S.C. 8432(c)); CSRS employees get nothing.
What is the CSRS minimum retirement age?
Age 55 with 30+ years, age 60 with 20+ years, or age 62 with 5+ years. Early voluntary retirement (age 50 with 20 years, or any age with 25 years) requires OPM authorization, and involuntary separation qualifies on the same terms; both are reduced 1/6 of 1% per month under 55 (5 U.S.C. 8336(d), 8339(h)). Leave earlier with 5+ years and the annuity is deferred to 62. Unlike FERS, there's no MRA that varies by birth year.