401(k) Contribution Calculator — Employer Match Optimizer, 2026 Limits & Growth

You & your pay required

Salary ($/yr, gross)

Your age (end of 2026)

Pay frequency Your contribution (% of pay, Traditional + Roth combined)

⚙️ Mid-year? Anchor to your year-to-date

Contributed so far in 2026 ($, you — not the employer) Paychecks left this year (count them on your pay schedule)

Leave both at 0 to model a full clean year. With real numbers, the max-out pacing below switches to "what to set now so the remaining checks land exactly on the limit."

Employer match the free money

Formula My plan has a true-up (year-end make-up match)

Most plans match per paycheck: a check where you contribute nothing earns no match — even if you already maxed the year. A true-up plan re-runs the formula on your full-year totals and pays back the difference. Your Summary Plan Description (or HR) knows which you have; it changes the front-loading math below completely.

Growth the long game

Retirement age

Expected annual return (%)

Assume I keep contributing at this level every year

Projections are in future (nominal) dollars at a flat return — real markets zig-zag and limits rise most years, so treat these as illustrations of scale, not predictions.

The free-money check

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Match you capture

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Minimum % for full match

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Your contribution

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Your 2026 limit

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% of limit used

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To max out exactly

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Paycheck by paycheck

Each bar is one paycheck: your contribution plus the match it earns. If your percentage would hit the annual limit before the last check, contributions stop mid-year — and in a per-paycheck plan (no true-up) the match stops with them. That's the front-loading trap: same money in, less free money back.

What it becomes by

Contributing like this every year

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…of which the match alone

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Just this one year's money

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2026 limits cheat-sheet reference

Limit	Amount	Notes
401(k)/403(b)/TSP employee deferral	$24,500	Traditional + Roth combined; shared across all employers in the year
Catch-up, age 50+	+$8,000	Total $32,500
"Super" catch-up, ages 60–63	+$11,250	Total $35,750 — replaces (not stacks on) the $8,000; back to $8,000 at 64
Roth catch-up mandate	$150,000+	Earned over $150k (prior-year wages) and 50+? Catch-up dollars must go in as Roth
Total incl. employer (§415(c))	$72,000	Employee + employer + after-tax combined (catch-ups ride on top)
IRA (separate from all the above!)	$7,500	+$1,100 catch-up at 50+ — you can max the 401(k) and an IRA
HSA (self / family)	$4,400 / $8,750	+$1,000 catch-up at 55+; the only account that skips FICA too

Sensible order for most people: 1) contribute enough for the full match (an instant 50–100% return), 2) max the HSA if you have one (triple tax break), 3) then push the 401(k)/IRA as far as your budget allows. For the Traditional-vs-Roth question and the per-paycheck take-home impact, use our take-home paycheck calculator — it models your actual withholding.