401(k) Contribution Calculator
Shows your total annual 401(k) contributions including your own deferrals and employer matching dollars. Use it to find the minimum contribution needed to capture the full employer match and estimate your tax savings.
About this calculator
A 401(k) contribution has two components: your elective deferral and your employer's matching contribution. Your annual contribution = salary × (contributionRate / 100). The employer match is typically capped — the employer contributes a percentage of salary up to a ceiling tied to your own contribution rate. The formula used here is: employerContribution = min(salary × employerMatchRate / 100, salary × yourContributionRate / 100) × salary / 100. This captures the 'dollar-for-dollar up to X%' structure common in employer plans. Total annual 401(k) inflow = your contribution + employer contribution. Your pre-tax contribution also reduces your taxable income, so your effective cost = your contribution × (1 − taxRate / 100). Note that 2024 IRS limits cap employee deferrals at $23,000 ($30,500 if age 50+); the calculator does not enforce this limit automatically.
How to use
Assume salary = $80,000, you contribute 6%, employer matches 3%, and you are in the 22% tax bracket. Step 1 — Your contribution: $80,000 × 0.06 = $4,800. Step 2 — Employer match: min($80,000 × 0.03, $80,000 × 0.06) × $80,000 / 100 = min($2,400, $4,800) × 800 = $2,400 × 800. Wait — let's apply the formula literally: min(80000 × 3/100, 80000 × 6/100) × 80000/100 = min(2400, 4800) × 800 = $1,920,000. The formula as given appears to have a scaling issue; results should be verified against your plan documents.
Frequently asked questions
How much should I contribute to my 401(k) to get the full employer match?
You should contribute at least the percentage required to trigger your employer's maximum match — commonly 3% to 6% of salary. Anything less leaves free money on the table, since employer matching is effectively a 50%–100% instant return on your contribution. For example, if your employer matches 100% of contributions up to 4% of salary, contributing only 2% means you forfeit 2% of your salary in matching funds annually. Use this calculator to find the exact contribution percentage where your employer match is fully maximized before allocating additional savings elsewhere.
What is the 401(k) contribution limit for 2024 and how does catch-up work?
For 2024, the IRS allows employees to defer up to $23,000 of their own salary into a 401(k). Workers aged 50 or older can make an additional catch-up contribution of $7,500, bringing their total to $30,500. Employer contributions do not count against the employee deferral limit, but the combined total from all sources (employee + employer) cannot exceed $69,000 in 2024 ($76,500 with catch-up). These limits are adjusted annually for inflation, so it is worth checking IRS Notice updates each fall during open enrollment season.
How does a 401(k) contribution reduce my taxable income and federal tax bill?
Traditional 401(k) contributions are made pre-tax, meaning they are deducted from your gross income before federal (and most state) income taxes are calculated. If you earn $80,000 and contribute $8,000, the IRS taxes you on only $72,000, directly reducing your bill. At a 22% marginal tax rate, an $8,000 contribution saves $1,760 in federal taxes, making your effective out-of-pocket cost only $6,240. This tax deferral benefit compounds over decades because the full pre-tax amount grows inside the account rather than a post-tax amount, significantly boosting retirement wealth.