How to use this calculator
Enter your birth year, pay schedule and salary. You get the exact dollar amount or % to set, including catch-up, the age 60–63 super catch-up and your employer match. Nothing you type leaves your browser.
- Pick 2027 to plan next year (open enrollment, New Year's resolution), or rest of 2026 if you want to catch up before December 31.
- Add your birth year. If you turn 50 or older in that year, the catch-up is added for you.
- Choose how often you're paid and check the number of paychecks left. Not sure? Use “Count from my next payday”.
- Add your salary to see the answer as a % of pay, and anything you've already put in this year, including at a previous job.
- Optional: open Employer match so we can warn you if a % election would make you miss match money.
How it's calculated
All math is done in whole cents, so there are no rounding surprises.
- Your limit = the employee deferral limit ($25,500 for 2027, $24,500 for 2026) plus a catch-up if you are 50 or older on December 31: $8,500, or $11,750 if you turn 60, 61, 62 or 63 that year.
- Left to contribute = your limit minus what you've already put in this year.
- Per paycheck = left to contribute ÷ paychecks left, rounded up to the next whole dollar. Rounding down would leave you a few dollars short; rounding up means the last paycheck is a little smaller, and plans stop deferrals at the limit.
- % of pay = the smallest % in your plan's steps (whole %, 0.5% or 0.1%) that still reaches the limit after payroll drops fractions of a cent. Gross pay per paycheck is salary ÷ 52, 26, 24 or 12.
- Match check: we play out every paycheck. If a % election reaches the limit early, the paychecks after it get no match unless your plan does a year-end true-up.
Three worked examples
Maya, 34, salary $95,000, paid every 2 weeks
Limit $25,500 over 26 paychecks: $981 a paycheck (the last one about $975), or 27% of pay. Her employer matches 100% up to 4%, and spreading contributions keeps the full $3,799.90 match.
Robert, 61 in 2027, salary $180,000, paid twice a month
The super catch-up applies: $25,500 + $11,750 = $37,250. That's $1,553 a paycheck (last about $1,531) or 21%. His 2026 wages were over $155,000, so the $11,750 catch-up must go in as Roth.
Priya, 52, salary $120,000, weekly, changed jobs in July
She has put in $15,000 across both jobs. The 2026 limit with catch-up is $32,500, so $17,500 is left over 12 weekly paychecks from October 9: $1,459 a paycheck or 64%. That's a big bite of take-home pay, so we flag it.
And a front-loading trap: at $300,000 with a 100% match up to 5%, a 9% election hits the limit on paycheck 25 of 26 and can cost $576.92 of match. Setting $981 a paycheck instead loses nothing.
The Roth catch-up rule, in plain English
If you are 50 or older and earned more than $150,000 in Social Security wages (W-2 box 3) from your employer in 2025, your 2026 catch-up has to be Roth: taxed now, tax-free later. For 2027 the test is 2026 wages over a projected $155,000. Only the catch-up is affected; your first $25,500 can still be pre-tax. Wages from other employers don't count toward the threshold.
Plans have had to follow the rule since January 1, 2026 in good faith, and the final IRS regulations (opens in a new tab) generally apply from 2027. If your plan doesn't offer Roth, you may not be able to make catch-up contributions at all. Ask HR. See all figures side by side on the 2026 vs 2027 limits page.