401k Match Calculator
Enter your salary, your contribution percentage and your plan's match formula. The calculator shows the free money you collect each year, what contributing less leaves on the table, and what that gap becomes over twenty years of compounding.
Payroll pages explain enrollment; this one prices the decision. The match is the only instant 50-100% return in finance with no market risk - and the gap row is what declining it actually costs, in the only units that matter: years.
How to use
- Copy the match formula from your HR page - rate and cap both go in exactly as written.
- Enter your current contribution percentage; the matched slice is whatever the cap allows.
- Read the gap row first: if it is not zero, the raise you are declining is your own.
Frequently asked questions
How does an employer 401k match work?
The plan pays a percentage of what you contribute, up to a salary cap - the classic pattern matches 50 cents per dollar on your first 6%. Contribute under the cap and the difference is simply not paid; the match rewards presence, not effort.
How much should I contribute to get the full match?
Exactly the cap: at '50% of first 6%', contributing 6% earns the full 3% extra. Anything below is declining part of your compensation; anything above is fine but unmatched - good for tax reasons, invisible to the match.
Is the employer match really free money?
Yes, with one condition: vesting. Some plans hand the match over only after 2-3 years of service - leaving early forfeits it. Otherwise it is a 50-100% instant return no investment offers, before any market growth at all.
What does leaving the match on the table really cost?
The gap compounds: 1,800 a year declined at 5% real returns is about 60,000 over a 20-year career - the six-figure version of a rounding error. Order of operations: full match first, then high-interest debt, then everything else.