How the calculator works
It applies OPM's rules to the dates and salary you enter. Your retirement type comes from your age and service on the day you leave: unreduced at 62 with 5 years, 60 with 20, or your MRA with 30; reduced at your MRA with 10 (MRA+10); or deferred to 62 if you leave before any of those. The pension is high-3 × years × 1% (1.1% at 62 with 20+ years; 1.7% for the first 20 years under special provisions), cut 5% a year under 62 for MRA+10, then reduced 10% or 5% for a survivor benefit.
The supplement is your Social Security estimate at 62 × your civilian years (rounded, up to 40) ÷ 40, paid until 62. Over $25,560 of work income, it drops $1 for every $2.
What it leaves out: COLAs, raises before you retire, the partial-year detail of OPM's computation, CSRS components, and disability retirement. Read more in the guide to FERS retirement eligibility and the FERS supplement explainer.
Questions
How is the FERS pension calculated?
Your high-3 average salary × your years of service × 1%. If you retire at 62 or later with at least 20 years, the rate is 1.1%. Law enforcement officers, firefighters, and air traffic controllers get 1.7% for the first 20 years and 1% after that.
When can I retire under FERS?
With no reduction: at 62 with 5 years, 60 with 20, or your minimum retirement age (MRA, 55 to 57 depending on birth year) with 30. At your MRA with 10 to 29 years you can retire with a 5% cut for each year under 62. Special provisions employees can retire at 50 with 20 years, or at any age with 25.
What is the FERS supplement?
A monthly payment until 62 for people who retire before 62 on an unreduced immediate annuity. It is roughly your Social Security benefit at 62 × your years of civilian service ÷ 40. Military service does not count toward it, and MRA+10 and deferred retirements do not get it.
Does working after retirement reduce the supplement?
Yes. Above Social Security's annual exempt amount ($25,560 for 2027), the supplement drops $1 for every $2 you earn from work. Pension and investment income do not count. For special provisions retirees, earnings before the MRA are not counted.
How much does the survivor benefit cost?
A full survivor benefit (50% of your unreduced pension to your spouse) reduces your pension by 10%. A partial one (25%) costs 5%. Electing at least a partial benefit also lets your spouse keep FEHB after your death.
Does unused sick leave count?
Yes, for the pension amount: 2,087 hours adds one year of service to the formula. It does not count toward eligibility, the 20 years for the 1.1% rate, or a deferred annuity.
Sources: OPM, FERS computation and types of retirement; 5 U.S.C. 8412, 8415, 8421 and 8421a; SSA, 2027 earnings test exempt amount. Checked November 14, 2026.