Updated August 2, 2026. Quick answer: a FERS annuity is 1% of your high-3 average pay for every year of service — 1.1% if you go at 62 or later with 20 years behind you. Leave before 62 through the MRA+10 door and it is cut by five-twelfths of one percent for every full month you are short. Elect a survivor benefit and it is cut by 10% more. This calculator reproduces OPM’s own published examples to the cent.
The calculator
It matches OPM, and here is the proof
Anyone can publish a FERS calculator. The test is whether it reproduces the examples OPM publishes in its own handbook. This one does, on all three:
| OPM example | OPM publishes | This page |
|---|---|---|
| High-3 $53,221, 31 years 2 months, full survivor election | factor .311667, $16,587.23, $1,244.00 a month | 0.311667, $16,587, $1,244 a month |
| High-3 $48,000, 18 FERS years, age 63 with 20+ total | factor .198000, $9,504 | 0.198000, $9,504 |
| MRA+10 commencing at 58 years 0 months | factor .804167, $12,660.44 becomes $10,181.11 | 0.804167, $10,181 |
Where the 1.1% actually comes from
The statute is short: the annuity is “1 percent of that individual’s average pay multiplied by such individual’s total service”, and at 62 with 20 years “the percentage applied under such subsection shall be 1.1 percent, rather than 1 percent”. On a 30-year career that difference is 3% of your high-3 every year for life. Working a few extra months to reach 62 with 20 years is one of the few genuinely free wins in this system.
One nuance the handbook states and most summaries miss: for someone with a CSRS component, the 20-year test is met by total creditable service, while the 1.1% is applied only to the FERS years. This calculator assumes a pure FERS record; if you have a CSRS component, your CSRS part is computed under different rules entirely and the number here will be incomplete.
Your MRA, by year of birth
The minimum retirement age is not 55 for anyone born after 1969. From 5 CFR § 842.202:
| Year of birth | MRA |
|---|---|
| Before 1948 | 55 |
| 1948 | 55 and 2 months |
| 1949 | 55 and 4 months |
| 1950 | 55 and 6 months |
| 1951 | 55 and 8 months |
| 1952 | 55 and 10 months |
| 1953 to 1964 | 56 |
| 1965 | 56 and 2 months |
| 1966 | 56 and 4 months |
| 1967 | 56 and 6 months |
| 1968 | 56 and 8 months |
| 1969 | 56 and 10 months |
| 1970 and after | 57 |
The month you leave is worth more than you think
The reduction is five-twelfths of one percent for each full month the annuity starts before 62 — and “full month” is doing real work in that sentence. OPM’s Chart 8 is keyed to your age plus at least one day, so someone whose annuity starts the day after their 58th birthday has 47 full months to run, not 48, and takes .804167 rather than .800000. That is why OPM’s own Example 2 lands where it does, and this page computes it the same way, from the statute.
A note for the pedantic, since we checked every cell: one entry in OPM’s printed 1995 Chart 8 (age 60, 2 months) reads .913500 where the chart’s own uniform monthly step of .004167 gives .912500. Every other cell in the chart follows the statutory rule exactly. We compute from the statute at 5 U.S.C. § 8415(h)(1), which is the binding authority, and mention the discrepancy rather than quietly reproducing it.
Sick leave: real money, and none of it counts for getting out
Unused sick leave is added to your service for the computation. The statute is explicit that “these days will not be counted in determining average pay or annuity eligibility”. So it cannot make you eligible a day earlier, and it can add a year of annuity to a career that qualified anyway. At 2,087 hours to the year, a full year of banked sick leave on a $100,000 high-3 is about $1,000 a year, for life.
OPM converts it with a lookup chart that goes to the day and does not reduce to a clean formula — two OPM publications of it even disagree by an hour in one cell. This page uses the 2,087-hour basis and truncates to whole months, so treat the sick-leave portion as slightly conservative rather than exact.
What this does not include
The annuity is one of three legs. The FERS supplement bridges you to 62 if you left through an unreduced door; the TSP is the leg you actually control; and Social Security arrives on its own schedule. Whether the three add up is a different question: the gap between what you need and what you have.
Also excluded, deliberately: deposits and redeposits for prior service, part-time proration, refunded service, and any CSRS component. Each of those changes the number and none of them can be guessed at.
Computation, multipliers, the age reduction and the sick-leave rule from 5 U.S.C. §§ 8412, 8415 and 8419 and 5 CFR § 842.202; the worked examples, the accrual factor charts and Chart 8 from the OPM CSRS and FERS Handbook, Chapter 50. Read August 2026. General information, not advice, and not an official OPM estimate.
If the pension is a military one: retired pay is 2.5% or 2.0% a year of your high-3, and Guard service divides points by 360 — and the survivor election has a statutory price rather than an insurer’s: what SBP costs and what it buys.
Military service changes two of these rules: prior active service can be bought into a FERS annuity for 3% of the pay you earned then — usually requiring you to waive military retired pay, though reserve retirees are excepted — and at 65 TRICARE requires Medicare Part B or it ends.