# Retro pay calculator (2026)

Retro pay (retroactive pay) is wages you should have received earlier, paid as a lump on a later check — a raise with a past effective date, missed overtime, or a classification correction. Searchers type “retro pay calculator.” This page preloads an $80,000 salary plus a $4,000 retro lump so you can see regular take-home plus the supplemental sketch. It is not a second copy of the bonus calculator, the signing-bonus page, or the PTO payout page.

Payroll usually withholds federal tax on a retro lump with the IRS optional flat 22% on supplemental wages (37% above $1,000,000). Some employers fold it into a regular check and use the aggregate method instead. This engine shows the flat supplemental sketch so you can plan cash, not file a return. Year-end tax is still ordinary wages at your marginal rate.

FICA still applies to retro wages. Social Security stops at the $184,500 2026 wage base; Medicare does not. California adds a simplified PIT increment plus 1.3% SDI on the lump in this model. Texas has no state income tax on wages, so the state line on the same $4,000 retro is zero; federal and FICA stay.

Type a different lump in the bonus field if your back-pay amount is not $4,000. Use the bonus calculator for a generic supplemental field, PTO payout taxes for a vacation cash-out, or signing bonus after taxes for a $10,000 offer sample. Reviewed October 2, 2026.

## Sample estimates

### $80k CA single + $4k retro pay

- 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 TX single + $4k retro pay

- Gross: $80,000.00
- Federal income tax: $8,770.00
- Social Security: $4,960.00
- Medicare: $1,160.00
- State income tax: $0.00
- Net / take-home: $65,110.00 (effective tax 18.6%)
- Per paycheck net: $65,110.00 (1 periods)

Label: engine estimates, not pay stubs.

## FAQ

### What is retro pay on a paycheck?

Back wages paid later: a raise that started last month, missed overtime, or similar. This calculator treats the lump as extra gross this year, not a second salary.

### Is retro pay taxed at 22%?

Withholding often uses the IRS optional 22% supplemental rate (37% over $1M). Your Form 1040 still taxes it as ordinary wages. The stub can look harsher than the annual return.

### Is this the same as a bonus calculator?

Same supplemental engine. This URL matches “retro pay calculator” with a $4,000 back-pay sample, not a $10,000 signing bonus or a $5,000 PTO cash-out.

## Related

- [Bonus paycheck calculator](https://takehomecash.com/bonus-paycheck-calculator/index.md)
- [PTO payout taxes](https://takehomecash.com/pto-payout-taxes/index.md)
- [Signing bonus after taxes](https://takehomecash.com/signing-bonus-after-taxes/index.md)