# Paycheck calculator with 401(k) (2026)

This is the “with 401k” landing page: the form starts at 10% traditional 401(k) on an $80,000 California salary. It is not the 401(k) versus take-home comparison essay, which spends its words on 0% vs 10% side by side.

A traditional elective deferral reduces federal taxable wages and, in this model, typically California taxable wages. It remains in the Social Security and Medicare wage base. That is why FICA barely moves when you raise the 401(k) percent, while the federal and state income-tax lines fall.

Roth 401(k) is not modeled — Roth dollars do not reduce federal wages. Employer match is omitted because it is not employee cash. We do not enforce the annual IRS dollar cap.

Section 125 health premiums are a different lever: they generally reduce FICA as well. Reviewed August 24, 2026.

## Sample estimates

### $80k CA single, 0% 401(k)

- Gross: $80,000.00
- Federal income tax: $8,770.00
- Social Security: $4,960.00
- Medicare: $1,160.00
- State income tax: $3,210.42
- Net / take-home: $60,859.58 (effective tax 23.9%)
- Per paycheck net: $60,859.58 (1 periods)

### $80k CA single, 10% 401(k)

- Gross: $80,000.00
- Federal income tax: $7,010.00
- Social Security: $4,960.00
- Medicare: $1,160.00
- State income tax: $2,547.85
- Net / take-home: $55,282.15 (effective tax 20.9%)
- Per paycheck net: $55,282.15 (1 periods)

Label: engine estimates, not pay stubs.

## FAQ

### What is preloaded?

$80,000, California, single, 10% traditional 401(k), tax year 2026.

### Does 401(k) reduce Social Security?

Usually no. Traditional deferrals stay in the FICA base. Health premiums under a cafeteria plan generally reduce FICA wages.

### How is this different from 401(k) vs take-home?

That page is a 0% vs 10% explainer. This URL is the with-401(k) calculator, already set to 10%.

## Related

- [401(k) vs take-home pay](https://takehomecash.com/401k-vs-take-home-pay/index.md)
- [W-4 extra withholding](https://takehomecash.com/w4-extra-withholding/index.md)
- [Take-home pay calculator 2026](https://takehomecash.com/take-home-pay-calculator-2026/index.md)