Bonus Tax Calculator (Korea: how much of a performance bonus you keep)

How it works

A bonus is ordinary earned income, taxed together with your salary for the year. The tax is estimated on a year-end-settlement basis: income tax on (salary + bonus) minus income tax on salary alone. Each uses the earned-income deduction, your other deductions, the 6–45% rate table and the earned-income tax credit; local income tax adds 10%. Social insurance on the bonus = health 3.595% + long-term care (13.14% of that) + employment 0.9% ≈ 4.97%. National pension is left out: its monthly base is capped and is set from the previous year’s pay. The tax actually withheld on payday follows the simplified withholding table and is corrected in the February year-end settlement.

⚠ Estimates for information only — not financial advice.

FAQ

Is a bonus taxed at a special rate?

No. In Korea a bonus is earned income like your salary. It feels heavily taxed because it sits on top of your salary and falls in your highest brackets.

Why was more tax withheld than this estimate?

Payday withholding on a bonus month uses the simplified table on an averaged monthly amount and can over- or under-shoot; the difference is settled in the February year-end settlement.

Checked 11 Nov 2026. Income Tax Act (2026): art. 47 earned-income deduction (70/40/15/5/2%, cap ₩20 million), art. 55 basic rates 6–45% (₩14m/50m/88m/150m/300m/500m/1bn), art. 59 earned-income tax credit (55% / 30% above ₩1.3m; limits ₩740k→660k→500k→200k by total pay); local income tax 10% of income tax (Local Tax Act art. 103-3). Employee social insurance on pay, 2026: health 3.595% (7.19% total, Health Insurance Policy Deliberation Committee, Aug 2025), long-term care 13.14% of the health premium (Long-Term Care Committee, Nov 2025), employment insurance 0.9%.