You contribute this year
$3,000
Enter a salary, a contribution rate and the match formula from your plan. The calculator reports what the employer adds this year, and what the gap between your rate and the match limit is worth by the time you retire.
No tax treatment is modelled, on either the deferral or the match. The projection assumes a constant annual return applied monthly, which is an assumption rather than a forecast, and it does not model vesting: an employer contribution that is not yet vested is in the account and not yet yours. The limits applied are the 2026 figures, being $24,500 of elective deferral for an employee under 50 and a combined limit of $72,000 across employee and employer money, and catch-up contributions are not modelled.
| Your contribution rate | You pay in | Employer adds | Total for the year | Employer share of salary |
|---|---|---|---|---|
| 1% of salary | $1,000 | $1,000 | $2,000 | 1.0% |
| 2% of salary | $2,000 | $2,000 | $4,000 | 2.0% |
| 3% of salary | $3,000 | $3,000 | $6,000 | 3.0% |
| 4% of salary | $4,000 | $4,000 | $8,000 | 4.0% |
| 5% of salary | $5,000 | $5,000 | $10,000 | 5.0% |
| 6% of salary | $6,000 | $6,000 | $12,000 | 6.0% |
| 7% of salary | $7,000 | $6,000 | $13,000 | 6.0% |
| 8% of salary | $8,000 | $6,000 | $14,000 | 6.0% |
| 10% of salary | $10,000 | $6,000 | $16,000 | 6.0% |
| 15% of salary | $15,000 | $6,000 | $21,000 | 6.0% |
An employer match is not a single number written into the tax code. It is a formula set by the plan, and the range of formulas in use is wide. The most common shape, and the one modelled here, matches a share of your salary deferral up to a stated limit of pay.
That last point is worth being explicit about, because it is the one place where a single-band model can mislead. A two-tier formula pays out at two different rates across two ranges of pay, so a contribution rate in the middle of the upper tier earns less per additional percent than one in the lower tier. Entering the equivalent maximum gets the ceiling right and flattens the path to it. If the shape of the path matters to your decision, the plan's own summary plan description is the authoritative source and it is required to state the formula.
The table below the calculator lists the same salary against every contribution rate from 1% to 15%, and the shape of the answer is the point. Up to the match limit, every additional percent of salary you contribute brings in an equal amount from the employer. Above the limit, additional contributions bring in nothing extra.
| Your rate | You pay in | Employer adds | Employer share of salary |
|---|---|---|---|
| 1% of salary | $1,000 | $1,000 | 1.0% |
| 3% of salary | $3,000 | $3,000 | 3.0% |
| 6% of salary | $6,000 | $6,000 | 6.0% |
| 8% of salary | $8,000 | $6,000 | 6.0% |
| 15% of salary | $15,000 | $6,000 | 6.0% |
$100,000 of salary against a plan matching 100% of the first 6%
The consequence is that the marginal return on a contribution is not constant, and at the bottom of the range it is enormous. The first percent of salary contributed under a 100%-of-the-first-6% plan is immediately matched dollar for dollar, which is a 100% return on that dollar before any investment return is counted. No other contribution available to a household behaves that way, and the match is why the general ordering of personal finance priorities puts contributing to the match limit above almost everything else.
On the default inputs the contribution rate is 3% against a limit of 6%, so $3,000 of match is left unclaimed every year. Projected at a 7% annual return over 25 years that unclaimed money would have become $202,518 — a figure that looks implausibly large until it is checked, and is not: $250 a month for 300 months at 7% is $202,518 by the ordinary annuity formula. The number is large because the horizon is long, not because the arithmetic is generous.
Two separate ceilings apply to a 401(k), and the most common error in calculator output is to report one as if it were the other. They constrain different things and they bind at different salaries.
The two bind at different points. The deferral limit is reached when salary × rate crosses $24,500, which at $100,000 of salary means a rate of 24.5%. The combined limit is reached when the sum of both contributions crosses $72,000, which requires either a large employer contribution or a salary high enough that the deferral alone approaches it. On the default inputs neither ceiling is close, which is the ordinary case and the reason both are stated rather than assumed away.
One further limit matters if the salary is high. Annual compensation above the annual compensation limit — $360,000 for 2026 — does not count towards the match calculation under many plan formulas, so a highly compensated participant can find that matching stops partway through the year in percentage terms. The plan document governs, and the summary plan description is required to say so.
These figures are the 2026 limits. The annually adjusted amounts are normally published in the autumn for the following year, which is the reason this page carries a scheduled refresh date and the reason a projection running several decades should be treated as a series of annual decisions rather than a single setting.
On the default inputs the account ends at $405,036 after 25 years, and $202,518 of that came from employer contributions and their growth. Half the balance is money the household did not put in. That proportion is a direct consequence of the match being the full 6% of salary while the household contribution is 3%.
Two effects compound together here and it is worth separating them. The employer money is contributed continuously, which makes it a monthly annuity; and it is invested from the month it arrives, which gives every dollar the longest possible time in the market. Late contributions in a long plan therefore do more work than their face value suggests, for the same reason the last decade of any compound projection is the largest.
There is also a behavioural point that the arithmetic cannot express but the numbers make obvious. A match is paid per pay period and depends on a deferral being in place during that period. A participant who suspends contributions for a year to improve cash flow does not simply delay the money; the match for that year does not accrue at all, and it does not come back later. The one-year cost on the default figures is $3,000 of match plus everything it would have grown into, which is roughly $16,500 by year 25 at a 7% return.
For the part of the decision that involves what the balance eventually produces as income, the retirement savings calculator converts a projected balance into a withdrawal figure. For the effect of the contribution rate on the balance rather than on the match, the compound interest calculator isolates that variable.
Take $100,000 of salary, a 3% contribution rate, and a plan matching 100% of the first 6%. The employee deferral is $100,000 × 3 ÷ 100 = $3,000, well below the $24,500 elective deferral limit, so no ceiling applies.
The employer match is calculated on the lower of the contribution rate and the limit: min(3, 6) = 3, then $100,000 × 3 ÷ 100 × 100 ÷ 100 = $3,000. The combined $6,000 is far below $72,000, so the second ceiling does not bind either.
The unclaimed match is the difference between what the formula pays at the limit and what it pays at your rate: $100,000 × 6 ÷ 100 − $3,000 = $3,000 a year. Projected as $250 a month for 300 months at 7% a year, which is 0.5833% a month, the annuity factor is (1.005833300 − 1) ÷ 0.005833 = 810.07, giving $202,518.
A few cents of disagreement with your own working is the rounding order. More than that means one of the two implementations is wrong, and the corrections page explains how to report it.
At least as much as the match limit in your plan's formula, and not more for the purpose of the match itself, since contributions above the limit bring in no additional employer money. On the default plan that means 6% of salary. What this page does not do is advise on contributions above the limit, which is a different question about taxes and about the returns available in the plan versus elsewhere. The table below the calculator shows the employer contribution at every rate from 1% to 15% so the ceasing point is visible.
The elective deferral limit of $24,500 for 2026 applies to your own salary deferrals only, and the catch-up amounts for participants aged 50 and over sit on top of it. The combined limit of $72,000 for 2026 applies to your deferrals plus the employer's contributions together, and catch-up contributions are outside it. A participant watching only their own deferral can therefore approach the combined limit without noticing, particularly where the employer contributes a large percentage or a profit-sharing allocation is involved. The plan administrator is the authoritative source.
That formula pays a maximum of 4% of salary, being 3% plus 1%, so entering a match rate of 100 with a limit of 4 reproduces the ceiling correctly. It does not reproduce the path to the ceiling, because the real formula pays 100% on the first 3% and 50% on the next 2%, so a rate of 4% earns less than the model shows. Read your plan's summary plan description for the exact tiers, and treat the model here as the ceiling rather than as a schedule of every intermediate rate.
That depends on the vesting schedule, which this page does not model. Employer contributions are commonly subject to a schedule under which they become yours over a period of years, and a participant who leaves before the schedule completes forfeits the unvested portion. Your own deferrals are always fully yours. The projected balance here treats every employer dollar as owned on the day it is made, which is the right assumption only for a participant who stays long enough to be fully vested.
Because the horizon is long and the contributions are monthly. On the default figures $3,000 a year is $250 a month, and 300 monthly payments at 7% a year become $202,518. The figure is identical to the projected value of the match actually collected, which is the point: forfeited match and never-made contribution are the same arithmetic. If the projected number looks too large to be true, the check is to compute it as a monthly annuity by hand, as the last section does.
Related calculatorsCompound interest calculator · Retirement savings calculator · Goal savings calculator
Cluster us/investing · Unit us-investing-401k-match-calculator · Engine compound-growth / match · Method: Employee deferral is salary × contribution rate, capped at the elective deferral limit. Employer match is the lower of the contribution rate and the plan's match limit, multiplied by the match rate and by salary. The two are then tested against the combined limit that applies to employee and employer money together. Contributions are projected as a monthly annuity at the stated annual return.