# Roth vs traditional 401k paycheck calculator (2026)

On an $80,000 California salary, 0% traditional 401(k) is the Roth-like paycheck and 10% traditional is the pretax path. There is no Roth box: a Roth deferral is after-tax, so take-home matches 0% traditional at the same wage.

Traditional elective deferrals reduce federal taxable wages and, in this model, typically California taxable wages. They stay in the FICA base: Social Security 6.2% and Medicare 1.45% still apply to the deferred dollars. That is why FICA barely moves between the 0% and 10% rows while federal and state income tax fall.

Roth dollars do not leave federal wages, so they do not change income-tax withholding or FICA in this sketch. Employer match is omitted because it is not employee cash. We do not enforce the IRS elective-deferral dollar cap. Health premiums are a different lever — they generally reduce FICA too.

Drag the 401(k) percent from 0 toward 10 to watch the traditional path. Reviewed October 2, 2026.

## Sample estimates

### $80k CA single, 0% traditional (Roth-like take-home)

- 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% traditional 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

### Where is the Roth 401(k) box?

There isn’t one. Roth take-home matches 0% traditional on the same wage. Compare that row with 10% traditional below.

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

Usually no. Traditional deferrals stay in the FICA wage base. That is the FICA note that separates this from an HSA or cafeteria health premium.

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

That page preloads 10% traditional. This URL starts at 0% to show Roth-like take-home and names the missing Roth field.

## Related

- [401(k) vs take-home pay](https://takehomecash.com/401k-vs-take-home-pay/index.md)
- [Paycheck calculator with 401(k)](https://takehomecash.com/paycheck-calculator-with-401k/index.md)
- [HSA paycheck calculator](https://takehomecash.com/hsa-paycheck-calculator/index.md)