401(k) Impact on Paycheck Calculator

Pre-tax 401(k) contributions reduce your taxable income, which means you don't lose the full contribution amount from your take-home pay — you save the taxes that would have been owed on that money. A $500 bi-weekly traditional 401(k) contribution for someone in the 22% federal bracket and 5% state bracket actually costs only $500 × (1 - 0.22 - 0.05 - 0.0765) = approximately $327 in reduced take-home pay. The other $173 would have gone to taxes anyway.

This calculation — comparing gross pay minus the 401(k) amount against the actual net pay reduction — is often surprising to workers who assume a $500 contribution means $500 less in their pocket. The real cost is substantially less.

Use this calculator to find your optimal 401(k) contribution level. Compare scenarios: 6% contribution vs. 10% vs. maximum ($23,500/year in 2026 if under 50, $31,000 if 50+). See the annual tax savings and reduced take-home for each option. The "sweet spot" is often maximizing up to the employer match, since unmatched 401(k) contributions involve a trade-off between tax savings now and liquidity today.