401(k) Max Out Calculator

Quick answer: the max-out formula

For 2026 you can defer up to $24,500 into a 401(k), 403(b), governmental 457(b) or the TSP, plus $8,000 if you're 50 or older by December 31, or $11,250 instead if you're 60 to 63 (IRS). Contributions have to come out of a paycheck dated in 2026: unlike an IRA, you can't top up a 401(k) next spring.

(Your limit − contributed so far) ÷ paychecks left = amount per paycheck

Example: ($24,500 − $12,000) ÷ 5 = $2,500.00 a paycheck. On a $100,000 salary paid every two weeks that's 65% of pay, and take-home drops by about $2,071.15 a paycheck in Texas.

The calculator above does this for you, rounds to a percent your payroll will accept, shows what it does to your take-home pay, and checks two things most max-out calculators skip: the employer match you can lose by maxing out early, and the Roth rule for catch-ups.

What percent maxes out a 401(k) for the whole year

If you're setting your election for a full year, divide the limit by your salary. These rows come from the calculator: paid every two weeks (26 paychecks), starting from zero, rounded up to a whole percent.

Rounding up means you'll usually reach the limit a little before the last paycheck; your plan should stop deferring at that point. If your plan matches each paycheck, read the true-up section before choosing a high rate.

Catching up before December 31

Most people who want to max out decide part-way through the year. The amount you need depends on what you've already put in and how many paychecks are left. Example: $100,000 salary, paid every two weeks, 5 paychecks left, single filer in Texas.

Two practical points: payroll changes often take one or two pay cycles to kick in, so count only the paychecks your new election will actually reach; and some plans cap the election (for example at 50% or 75% of pay). When the amount needed is more than your paycheck, the calculator says it can't be reached.

Whole percents and the last paycheck

Payroll systems usually take a whole percent of each paycheck, not a dollar amount. So the calculator rounds the exact rate up — rounding down would leave you short. With $18,000 already in and 5 paychecks left on $100,000, you need $1,300.00 a paycheck, which is 33.8% of pay. That rounds up to 34% ($1,307.69 a paycheck), and the plan stops at the limit on the final paycheck. If your plan accepts dollar amounts, enter $1,300.00 instead.

Front-loading and the employer match (true-ups)

Many employers match each paycheck. If you contribute a high percentage and hit the limit in, say, October, your contributions stop — and so does the match for the rest of the year. Some plans fix this with a year-end true-up that pays the match you'd have received over the whole year; others don't (Betterment explains true-ups). Your plan's summary plan description says which applies.

Example from the calculator: a $130,000 salary, a dollar-for-dollar match on up to 4% of pay, contributing 25% from January. You'd reach $24,500 on paycheck 20 of 26 and get no match on the last 6 — $1,200 of match lost without a true-up. Spreading it evenly at 19% gets the same $24,500 in and keeps the full match.

Enter your match and a rate in the "Test a contribution rate" box to check your own plan.

Catch-ups at 50+ and the 60–63 super catch-up

Your catch-up depends on your age on December 31, not on your birthday paycheck. If you turn 50 in December, you can make the full catch-up all year.

The bigger 60–63 catch-up comes from the SECURE 2.0 Act; at 64 it drops back to $8,000 (Notice 2025-67). Employer money doesn't count toward these employee limits, but everything except catch-ups counts toward the separate $72,000 total cap.

The Roth catch-up rule for higher earners

If your Social Security wages (W-2 box 3) from the employer were more than $150,000 in 2025, your 2026 catch-up contributions must be Roth — taxed now, not deducted (Notice 2025-67). Your first $24,500 can still be pre-tax. Final regulations apply from 2027; for 2026 plans use a good-faith reading of the rule (EY summary of the final regulations). If your plan has no Roth option, it generally can't let these higher earners make catch-ups at all; everyone else can still make pre-tax catch-ups.

What it costs: a 55-year-old earning $170,000 who has already put in $24,500 and wants the $8,000 catch-up over 5 paychecks. With 2025 wages of $160,000 the catch-up must be Roth, and take-home falls by $1,600.00 a paycheck; with 2025 wages of $140,000 it can be pre-tax and take-home falls by only $1,216.00.

Changed jobs this year? Avoid an excess deferral

The $24,500 limit is per person, not per employer, across 401(k), 403(b), TSP and SIMPLE plans (a governmental 457(b) has a separate limit of its own). Your new plan doesn't know what you put into the old one, so add both into "contributed so far". If you go over, ask a plan to return the excess by April 15 of the next year; otherwise the excess is taxed in the year you contributed it and again when it comes out (IRS). Each employer's match is separate.

Planning to max out in 2027

The 2027 limit is projected to be $25,500 (Milliman's estimate; the IRS usually publishes in late October or November). At that limit, a $100,000 salary needs 26% of pay and $150,000 needs 17%. Choose 2027 in the calculator, and see every 2027 figure on our 2027 limits page.

What this calculator doesn't cover

• 403(b) plans with the 15-years-of-service catch-up, and the 457(b) "double" catch-up near retirement.
• SIMPLE 401(k) and SIMPLE IRA limits, which are lower.
• After-tax (non-Roth) contributions and "mega backdoor" conversions.
• Plans that cap your election or block mid-year changes. Ask HR how soon a change takes effect.

To see what any contribution rate costs you over a full year, with the match, use the 401(k) paycheck calculator.

Common questions

Can I contribute to my 401(k) after December 31 for this year?

No. 401(k) deferrals have to come out of paychecks dated in the calendar year. That's different from an IRA or HSA, where you can contribute for the year until the tax filing deadline.

Does the employer match count toward the limit?

No. The $24,500 limit covers your own deferrals. Employer contributions count only toward the $72,000 total cap.

What happens if I go over the limit?

If it's all in one plan, payroll should stop you. Across two employers it's up to you: ask for the excess back by April 15, or it's taxed twice.

Should I max out my 401(k) or pay off debt first?

Get the full employer match first, then compare the interest rate on your debt with what you expect to earn. High-interest debt usually comes first; our debt payoff calculator shows the trade-off.

Is maxing out worth it if I can't afford the drop in pay?

Only save what your budget allows. A traditional contribution lowers take-home by less than you save, because of the income tax you don't pay now — the calculator shows the real drop.

Sources

1. 401(k) limit increases to $24,500 for 2026, IRA limit increases to $7,500 (IR-2025-111) — Internal Revenue Service. Accessed October 14, 2026.
2. Notice 2025-67: 2026 limitations for retirement plans — Internal Revenue Service. Accessed October 14, 2026.
3. IRS publishes final regulations implementing changes to retirement plan catch-up contributions — EY Tax News. Accessed October 14, 2026. Secondary source summarizing Treasury Decision 10033.
4. Consequences to a participant who makes excess deferrals to a 401(k) plan — Internal Revenue Service. Accessed October 14, 2026.
5. True-ups: what are they and how are they determined? — Betterment. Accessed October 14, 2026. Secondary source.

Research checked October 14, 2026. 2027 figures are labelled projected until the IRS publishes them.