2026 401(k) paycheck guideSee how retirement contributions change take-home pay before payroll runs
Use the state selector to open the 401(k) calculator that matches where payroll rules apply, then compare contribution rates, paycheck impact, employer match, and projected retirement value in one route.
What the 401(k) calculator estimates
A 401(k) paycheck calculator shows two things at once: how much a contribution changes current take-home pay and how much that contribution could grow over time.
Because traditional 401(k) deferrals are usually pre-tax for federal withholding, the drop in net pay is often smaller than the contribution amount itself.
Inputs to gather before you model a contribution
- State where payroll rules apply
- Gross pay for the paycheck
- Contribution rate or contribution amount
- Employer match details when offered
- Current balance, years to retirement, and assumed return if you want a projection
Why the state route still matters
Federal tax savings drive most of the immediate paycheck change, but state tax treatment can also move the final net-pay result.
That is why a 401(k) contribution can change take-home pay differently in California than it does in Texas or Florida.