Only the slice above a bracket boundary takes the higher rate. A progressive deduction produces the same tax as calculating each slice separately.
Find the taxable base first
The basic rates apply to the comprehensive taxable income base of a resident. For an employee, contract salary, gross taxable salary, employment income after its deduction, taxable base, calculated tax and final tax are different figures. This is reference information, not individual tax advice.
| Step | What to check |
|---|---|
| Gross salary | Annual employment income with non-taxable items distinguished |
| Employment income amount | Gross salary less the employment-income deduction |
| Taxable base | Amount after applicable income deductions; use this in the rate table |
| Calculated tax | Basic rates applied before tax credits and reductions |
| Final tax and settlement balance | Tax after credits, then the difference against tax already withheld |
A KRW 50 million taxable-base example is not the tax on a KRW 50 million salary. If you have other income, an employment withholding statement alone may not establish your full taxable base.
Basic rate table
| Taxable base in KRW | Rate | Progressive deduction in KRW |
|---|---|---|
| Up to 14m | 6% | 0 |
| Over 14m to 50m | 15% | 1,260,000 |
| Over 50m to 88m | 24% | 5,760,000 |
| Over 88m to 150m | 35% | 15,440,000 |
| Over 150m to 300m | 38% | 19,940,000 |
| Over 300m to 500m | 40% | 25,940,000 |
| Over 500m to 1bn | 42% | 35,940,000 |
| Over 1bn | 45% | 65,940,000 |
Calculated national tax = taxable base × bracket rate − progressive deduction
The deduction compensates for the lower rates on earlier slices. The NTS source labels its published table for tax years 2023–2025; the Korean guide also links Income Tax Act Article 55 for the statutory rates. Always check the law and table for the income year you are settling.
Calculate two ways
Example · KRW 50m taxable base
- By slices: 14m × 6% + 36m × 15% = 840,000 + 5,400,000 = KRW 6,240,000.
- Using the deduction: 50m × 15% − 1,260,000 = KRW 6,240,000.
Example · KRW 100m taxable base
- By slices: 840,000 + 5,400,000 + 38m × 24% + 12m × 35% = KRW 19,560,000.
- Using the deduction: 100m × 35% − 15,440,000 = KRW 19,560,000.
Crossing the KRW 50m boundary
Example · KRW 50m versus KRW 51m taxable base
- KRW 50m base: KRW 6,240,000 calculated tax.
- KRW 51m base: 51m × 24% − 5,760,000 = KRW 6,480,000.
- Difference: KRW 240,000, or 24% of the extra KRW 1 million base.
- This excludes credits, reductions and local income tax. A pay-rise comparison also needs insurance and deduction changes.
Reconcile a calculator result with payroll
- Match the income year and use taxable base rather than contract salary.
- Compare calculated tax with calculated tax, before comparing final tax or refunds.
- Record the taxable base, bracket rate and progressive deduction so payroll can reproduce the calculation.
- The stock-option tool estimates the tax difference after adding exercise income to your input taxable base. It does not rebuild every employment deduction and tax credit.
Example question: “I used a KRW 51 million taxable base and calculated KRW 6.48 million before credits. Can you confirm that I am comparing the same income year, taxable base and stage of the settlement?” Never treat calculated tax as the final cash amount payable.