How we calculate KPERS estimates

For the rules themselves, see the benefit formula, how KPERS 3 works and retiring early.

What the calculator doesn't cover

• Your final average salary. We use the number you enter; KPERS works it out from your records, with its caps.
• KPERS 2 early cuts and option factors at ages KPERS hasn't published, and every KPERS 3 option except the Base Benefit.
• The dollar amount of a KPERS 1 or 2 partial lump sum (KPERS's present-value factors aren't published).
• The lower starting amount of a KPERS 3 self-funded COLA.
• Disability benefits, purchase costs, taxes and health premiums.

How we check the math

Each KPERS worked example below is recomputed by the same code the calculator uses, and the tests also check the printed figure in KPERS's document.

Where KPERS's publications differ

• KLRD's 'KPERS Tier 3' page (Dec. 18, 2024) says a $4,000 lump sum is paid at a retiree's death. K.S.A. 74-4989 (L. 2024, ch. 65) and KPERS's FY 2027 budget narrative say $6,000 (raised from $4,000 in 2024). The task brief also mentioned $4,000. We use: Use $6,000 (statute and KPERS). The KLRD page appears not to have been updated.
• The task brief describes an automatic KPERS 2 COLA. KLRD (2021) and KPERS's FY 2027 budget narrative say it was eliminated effective July 1, 2012 in exchange for the 1.85% multiplier; K.S.A. 74-49,213 is not in the 2026 statutes. K.S.A. 74-49,134(c) (L. 2011, ch. 98) still describes a KPERS 2 choice between a COLA with 1.4% and no COLA with 1.75%, conditioned on IRS approval. We use: Settled by the valuation (p. 157): only KPERS 2 members who retired before July 1, 2012 get the 2% COLA; others get none. K.S.A. 74-49,134's election was ruled impermissible by the IRS (valuation p. 156, for the parallel KPERS 1 election).
• The task brief mentions 'the 1.75% multiplier'. Current law: KPERS 1 earns 1.75% for service before January 1, 2014 and 1.85% after (purchased service 1.75%); KPERS 2 earns 1.85% on all service for retirements on or after July 1, 2012. We use: The calculator uses the statutory split.
• KPERS 3 Plan Design: total account $185,754 on PDF p. 23 but $185,755 on p. 24 (106,258 + 79,497 = 185,755); benefit $14,222 on pp. 24 and 32 but $14,221 on p. 25; dividend what-if $15,097 on p. 29 but $15,096 on p. 32. We use: Rounding of unrounded balances; tests use the sums and accept $1 differences.
• The FY 2027 budget narrative (PDF p. 13) repeats a 2014 statement that assumed return minus 2% 'currently ... equals 6%'; the same document gives a 7.0% assumed return (PDF p. 11) and KPERS's Nov. 2024 presentation says the rate is 'currently 5%'. We use: Use 5% (7.0% - 2%). The 6% line is a historical statement from when the assumption was 8%.
• KLRD Tier 3 (Dec. 2024) gives employer contributions of 12.68% for FY 2026; KPERS's budget narrative gives the State/School rate as 11.68% for FY 2026. We use: Use KPERS's 11.68%. The 1.00-point gap may be the separate death and disability contribution; recorded in needsValidation.
• K.S.A. 74-49,204 and 74-49,313 refer to the 180-day waiting period 'as provided in K.S.A. 74-4914(10)', but the 180-day rule is in 74-4914(9) (there is no subsection (10)). We use: Stale cross-reference; the rule itself is the same (60 days at 62 or older, 180 days under 62).
• K.S.A. 74-4914(1) and the valuation (p. 151) give KPERS 1 normal retirement at 'age 65'; the Membership Guide (p. 12), Pre-Retirement Guide (p. 6) and webinar (slide 10) say 'Age 65 with 1 year of service'. We use: Follow KPERS's member publications: 65 with 1 year.
• K.S.A. 74-4914(1) adds 'years of attained age' and 'years of credited service'. KPERS counts age at the last birthday (not rounded) and rounds service to whole years (two quarters round up) (MG p. 12; PRG pp. 6-7; valuation p. 151). We use: The calculator uses age at last birthday and rounded service for eligibility and the benefit.
• KPERS 1 early examples show 5% at 60, 19% at 58 and 41% at 55 ($1,425, $1,215, $885 on $1,500) (PRG p. 7; webinar slide 12). The stated rate (0.2%/month 60-62, 0.6%/month 55-60) gives 4.8%, 19.2% and 40.8% ($1,428, $1,212, $888). We use: Use the rate; the examples round to whole percents. Tests check both.
• S.A. 74-4918's fixed life-certain percentages to KPERS 2. The Pre-Retirement Guide (p. 15) says KPERS 2 life-certain options use actuarial tables and depend on age (0.97398 for 10 years certain at 65, not 95%). We use: Follow KPERS: KPERS 2 life-certain amounts only where KPERS publishes the factor.
• The Pre-Retirement Guide (p. 22) counts the day after retirement as day one and says a July 1 retiree can start Sept. 1 (60 days) or Dec. 30 (180 days), a day later than a plain count gives. The KPERS 3 webinar (slide 61) says the waiting period 'begins with retirement date'; both application booklets (p. 19) say it 'begins the day after my retirement date'. We use: Follow the guide's worked example (the later, safer date) and the booklets' 'day after' start.
• The valuation (p. 153) says KPERS 2's 1.85% applies to those retiring 'on or after January 1, 2012'; K.S.A. 74-49,205 and the FY 2027 budget narrative say July 1, 2012. We use: No effect on current retirements; we cite July 1, 2012 (statute and KPERS's narrative).
• KPERS 3 surviving spouse option: the KPERS 3 disability and life insurance sheet (rev. 2/22, PDF p. 2) says five years of service; the valuation (p. 155) says 'a vested member'; KPERS 1 and 2 need 10 years (MG p. 8). We use: Same thing (vesting is five years). Pages state the tier difference.
• The KPERS 3 webinar's factor 12.2625 (slide 19) and the KPERS 3 Plan Design factor 13.061217 at 66 (2024) differ; the webinar doesn't say the age. We use: Only the age-66 factor is tied to an age; the webinar figure is tested as an example only.

Open questions for KPERS

• KPERS shows the KPERS 2 early cut only at ages 55, 58 and 60, rounded to whole percents. We show a KPERS 2 early amount only at those ages, labelled as KPERS's rounded example; at other ages we show the full benefit and the published cuts on either side, not a number.
• KPERS hasn't published its KPERS 3 annuity factors by age. The only one tied to an age is 13.061217 at 66. The calculator projects your account balance, then divides by an annuity factor you can see and change. It starts at 13.061217 (KPERS's age-66 factor) and says so; use the factor from your KPERS estimate for your age.
• KPERS publishes only two KPERS 2 option factors, both for a 65-year-old. We show KPERS 2 option amounts only when your case matches a published factor; otherwise the option shows 'ask KPERS'.
• A KPERS chart of KPERS 2 life-certain factors at ages 60 and 75 can't be read reliably from the PDF text. We quote the six values as a range (83.6% to 99.8%) and don't use them in the calculator.
• KPERS doesn't publish how much each KPERS 3 option or the 1%/2% COLA lowers your starting check. We show the base benefit only and list the other options without amounts.
• KPERS doesn't publish how big a KPERS 1 or 2 lump sum is for your age. We show the smaller monthly check (cut by the same percent) and KPERS's one dollar example, not your lump sum.
• KPERS says the KPERS 3 COLA is a fixed 1% or 2% each July 1 starting a year after you retire, but not whether it compounds or what it costs. We illustrate compounding yearly increases on the base amount and don't show the lower starting check.
• KPERS doesn't publish what buying service costs. We show what a year adds to the KPERS 1 or 2 benefit (KPERS's own table) and not the price.
• KPERS rounds your service to whole years; for KPERS 1 we don't know which part of your service gets the rounded quarter. We add or drop the rounded part on your newest (1.85%) service.
• KPERS's own sources count the working-after-retirement wait slightly differently. We use KPERS's worked example (July 1 retirement: Sept. 1 or Dec. 30), the later date.
• Kansas law counts KPERS 1 early-retirement months 'to the nearest whole month'; KPERS's guides just say 'each month'. We round to the nearest month (15 days or more rounds up).
• KPERS 1 service before 2014 earns 1.75% and after earns 1.85%; your split is on your KPERS statement. Unless you enter it, we assume steady full-time work from your hire date.
• One legislative source gives a different FY 2026 school employer rate than KPERS does. We use KPERS's figures. This doesn't change your benefit.

Sources: KPERS 1 & 2 Membership Guide (rev. 2/26); KPERS Pre-Retirement Planning Guide for KPERS 1 & 2 (1/25); KPERS 1 & 2 Retirement Application booklet (6/26); KPERS 3 Retirement Application booklet K3-15 (6/26); KPERS 1 & 2 Pre-Retirement Webinar slides; KPERS 3 Pre-Retirement Webinar slides; KPERS 2 Benefits at a Glance (rev. 5/25); KPERS 3 Benefits at a Glance (rev. 1/25); KPERS 3 Retirement Options (rev. 5/25); KPERS 3 Retirement Benefits (9/25); KPERS 3 Disability & Life Insurance (rev. 2/22); KPERS Working After Retirement flier for school employers; KPERS Actuarial Valuation as of Dec. 31, 2025 (July 16, 2026). Kansas Statutes are used only where KPERS's publications are silent.