Inputs you will enter
- High-3 average salaryYour highest 3 consecutive years of basic pay, averaged. Locality pay counts; overtime and bonuses do not.
- Years of serviceWhole years of creditable service, from your retirement service computation date. Include military time only if it is credited.
- Extra monthsMonths of service beyond the whole years, 0 to 11.
- Sick leave hoursOptional. Unused sick leave hours, converted to service with OPM's chart.
- Age at retirementYour age in whole years on the day you retire.
- Plus monthsMonths of age beyond the whole years, 0 to 11. The early-out reduction counts months under 55.
- Survivor electionNone, Partial or Full. The cost uses the CSRS formula on the base you pick.
How we compute it
We apply OPM's three tiers to your service: 1.5 percent of high-3 for each of the first 5 years, 1.75 percent for each of the next 5, and 2 percent for each year over 10 (OPM, retrieved 2026-10-13). The total is capped at 80 percent of high-3; credit for unused sick leave is added on top of the cap, and sick leave is credited only on an immediate annuity (OPM, retrieved 2026-10-13). We convert your sick leave hours to years and months and add them at 2 percent a year.
If you retire under 55 on an early out, the annual annuity is reduced by 1/6 of 1 percent for each full month you are under 55 (OPM, retrieved 2026-10-13). An early out needs 50 with 20 years or 25 years at any age, and either an OPM-approved early retirement at an agency in a major reorganization, reduction in force or transfer of function, or a discontinued service retirement after an involuntary separation that is not for misconduct (OPM, retrieved 2026-10-13). Immediate retirement otherwise needs 55 with 30 years, 60 with 20 or 62 with 5, with CSRS-covered service in one of the last two years. A deferred annuity can start at 62 with 5 years of civilian service.
A full survivor election reduces the annual annuity by 2.5 percent of the first $3,600 plus 10 percent of the amount over $3,600 (OPM, retrieved 2026-10-13). For a partial election, this estimate uses half the annuity as the base and applies the same formula.
CSRS Offset is not computed here. It covers employees whose CSRS service is also covered by Social Security. At 62, or when you first meet Social Security's basic requirements if later, OPM reduces the annuity by the lesser of two figures: the difference between your Social Security benefit with and without offset service, or your Social Security benefit times your years of offset service divided by 40. The reduction applies even if you have not applied for Social Security (OPM, retrieved 2026-10-13).
Voluntary contributions can add to a CSRS annuity. You can contribute up to 10 percent of the basic pay for your federal service to a voluntary account, with no government match, and at retirement each $100 buys $7 a year of additional annuity at 55, plus 20 cents for each full year over 55 (OPM, retrieved 2026-10-13). That additional annuity does not receive cost-of-living increases. The basic CSRS annuity does: it is increased by cost-of-living adjustments after retirement, and the first increase is prorated by the months you have been retired (OPM, retrieved 2026-10-13).
A worked example
An employee with a $95,000 high-3 and 32 years of service retires at 58 with no sick leave credit and a full survivor election. The formula is 5 x 1.5% + 5 x 1.75% + 22 x 2% = 7.5% + 8.75% + 44% = 60.25% of high-3, so the gross annuity is $95,000 x 60.25% = $57,237.50 a year. At 58 with 32 years the employee meets 55 with 30, so there is no age reduction. The full survivor election costs 2.5% x $3,600 = $90 plus 10% x $53,637.50 = $5,363.75, a total of $5,453.75, which leaves $51,783.75 a year, about $4,315.31 a month, before deductions.
The same high-3 on an early out at exactly 52 with 25 years gives 7.5% + 8.75% + 30% = 46.25%, or $43,937.50, then 36 months under 55 x 1/6 of 1% = 6 percent less, about $41,301.25 a year before any survivor election. Both are educational estimates on the assumptions shown.
What to do with your estimate
Convert your hours in the sick leave conversion tool and price a survivor benefit in the survivor benefit cost calculator. See what yearly COLAs could do to the annuity in the COLA impact calculator, read the CSRS guide for the rules in full, and use the FERS pension estimator for any FERS component. Every other estimator is on the federal benefits calculators page.
FFEBA is an education organization. If you want someone to look at your own numbers, we can match you with a Federal Retirement Consultant (FRC), a professional trained on federal benefits. The FRC designation is listed with FINRA. The first review is free, nothing is booked until you choose a time, and you are never obligated to work with anyone we introduce. Get matched with an FRC.
Questions about this calculator
How is a CSRS annuity calculated?
OPM takes 1.5 percent of your high-3 average salary for each of the first 5 years of service, 1.75 percent for each of the next 5, and 2 percent for each year over 10, and adds them together (OPM, retrieved 2026-10-13). Thirty years of service works out to 56.25 percent of high-3 before any reduction.
What is the maximum CSRS annuity?
The maximum is 80 percent of your high-3 average salary, plus credit for unused sick leave. The cap mainly affects employees with more than 41 years and 11 months of service (OPM, retrieved 2026-10-13).
How much does a CSRS survivor annuity cost?
A full spouse election reduces your annual annuity by 2.5 percent of the first $3,600 plus 10 percent of the amount over $3,600 (OPM, retrieved 2026-10-13). On a $57,237.50 annuity that is $90 plus $5,363.75, or $5,453.75 a year.
How much is the CSRS early retirement reduction?
On an early out at 50 with 20 years or at any age with 25, the annuity is reduced by 1/6 of 1 percent for each full month you are under 55, which is 2 percent a year (OPM, retrieved 2026-10-13). Disability retirement and certain special provision retirements are exempt.
What is CSRS Offset, and does this calculator include it?
CSRS Offset covers employees under both CSRS and Social Security. At 62, or later when you first meet Social Security's basic requirements, OPM reduces the annuity by the Social Security attributable to offset service, even if you have not applied for Social Security (OPM, retrieved 2026-10-13). The calculator explains it but does not compute it.
Is this the figure OPM will pay?
No. This is an educational estimate of the gross basic annuity on the inputs you enter. OPM computes the official figure from your records. Health and life insurance premiums and taxes come out of what is paid, and CSRS Offset can reduce it at 62.
Reviewed by the FFEBA education team. Last reviewed October 2026.
Sources
- U.S. Office of Personnel Management, CSRS computation, retrieved 2026-10-13
- U.S. Office of Personnel Management, CSRS eligibility, retrieved 2026-10-13
- U.S. Office of Personnel Management, RI 83-19, CSRS Retirement Facts 13: CSRS Offset, retrieved 2026-10-13
- U.S. Office of Personnel Management, CSRS and FERS Handbook, chapter 31 (CSRS voluntary contributions), retrieved 2026-10-13
- U.S. Office of Personnel Management, CSRS information, retrieved 2026-10-13
Every government figure on this page carries its source and retrieval date. Worked examples are educational estimates on the assumptions shown, not a projection of any person's benefit. FFEBA is an education organization, not a financial advisor.
