401k Calculator

What is a 401(k) calculator?

A 401(k) is an employer-sponsored retirement plan that lets you defer part of your paycheck before tax. Many employers also match a portion of what you save. This calculator projects your account balance at retirement using salary growth, your contribution rate, employer matching, expected investment returns, and inflation. IRS contribution limits are set for the 2025 tax year. All math runs in your browser.

Because traditional 401(k) salary deferrals reduce your taxable Box 1 wages before tax, they directly lower your income baseline calculated with the AGI calculator. If you are self-employed rather than in an employer plan, the 1099 tax calculator can estimate how much retirement savings reduce your taxable income alongside self-employment tax. For monthly take-home budgeting across needs, wants, and savings, the 50-30-20 rule budget calculator splits income into three buckets. Parents saving for tuition can use the 529 plan calculator to estimate monthly education savings alongside retirement deferrals. For housing costs that compete with retirement savings, the 28/36 rule calculator checks whether debt payments fit common lender guidelines.

How employer matching works

A common formula is a partial match on the first portion of your salary you defer. For example, 50% of the first 6% means your employer adds $0.50 for every dollar you contribute up to 6% of pay. On an $80,000 salary with an 8% deferral ($6,400), only the first 6% ($4,800) is matched, so the employer adds $2,400.

Here s is salary, L is the match limit as a decimal share of salary, and m is the employer match rate. Always contribute at least enough to capture the full match before saving elsewhere. Employer match is often described as immediate return on those dollars.

Compound growth over time

Each year the calculator adds your deferrals and employer match, then applies compound investment growth. The standard future-value model with a starting balance and recurring annual contributions is:

FV is the future balance, PV is your current balance, C is the annual contribution (yours plus match), r is the annual return, and n is years to retirement. This tool simulates year by year so salary increases and changing IRS limits can apply each year. Contributions are assumed to arrive mid-year, which slightly lowers growth compared with end-of-year deposits.

2025 contribution limits

Employee elective deferrals are capped under IRC section 402(g). For 2025, the base limit is $23,500 for workers under age 50. Catch-up contributions allow an extra $7,500 for ages 50 and older, and an enhanced catch-up of $11,250 applies for ages 60 through 63 under SECURE 2.0. Employer matching dollars count toward the separate section 415(c) combined limit, not your personal deferral cap.

Frequently asked questions