Japan has slightly higher effective income tax plus resident tax, and significantly higher employee social insurance contribution rates.
(For the Japan side, amounts are converted using a rough rate of 1 JPY ≈ 12 KRW, so figures are approximate.)
Korea vs Japan: Tax and Take‑Home Pay Comparison
All amounts below are in KRW per year.
| Annual salary | Country | Income tax + local/resident tax (rate) | Social insurance (rate) | Total deductions (rate) | Net income (net rate) |
|---|---|---|---|---|---|
| 50M KRW | Korea | 3,935,250 KRW (7.9%) | 4,858,692 KRW (9.7%) | 8,793,942 KRW (17.6%) | 41,206,058 KRW (82.4%) |
| Japan | 4,658,246 KRW (9.3%) | 7,375,000 KRW (14.8%) | 12,033,246 KRW (24.1%) | 37,966,754 KRW (75.9%) | |
| Difference | +3,239,304 KRW in Korea | ||||
| 100M KRW | Korea | 15,274,000 KRW (15.3%) | 9,717,383 KRW (9.7%) | 24,991,383 KRW (25.0%) | 75,008,617 KRW (75.0%) |
| Japan | 16,372,638 KRW (16.4%) | 14,750,000 KRW (14.8%) | 31,122,638 KRW (31.1%) | 68,877,362 KRW (68.9%) | |
| Difference | +6,131,255 KRW in Korea | ||||
| 200M KRW | Korea | 54,569,000 KRW (27.3%) | 19,434,766 KRW (9.7%) | 74,003,766 KRW (37.0%) | 125,996,234 KRW (63.0%) |
| Japan | 55,826,049 KRW (27.9%) | 29,500,000 KRW (14.8%) | 85,326,049 KRW (42.7%) | 114,673,951 KRW (57.3%) | |
| Difference | +11,322,283 KRW in Korea |
Structural Differences
1. Tax structure
Korea
National income tax with progressive rates.
Local income tax is 10% of the national income tax.
Earned income tax credit reduces the final tax burden for salary income.
No separate “resident tax” like in Japan; it is embedded as local income tax.
Japan
National income tax with progressive rates (broadly similar brackets to Korea at the top end).
Resident tax (jūminzei) of about 10% of taxable income is levied separately by local governments.
An additional Special Reconstruction Income Tax (2.1% of national income tax) applies.
Overall, when you combine national income tax, reconstruction tax, and resident tax, the effective tax rate is slightly higher than in Korea at equivalent income levels.
2. Social insurance burden
Korea (employee share, 2026 rates used in the model)
National Pension: about 4.75% of salary.
Health Insurance: about 3.595% of salary.
Long‑term Care: about 13.14% of the health insurance premium.
Employment Insurance: about 0.9%.
Total employee social insurance: roughly 9.7% of gross salary.
Japan (employee share, approximate)
Health insurance: about 5%.
Employees’ Pension (kōsei nenkin): about 9.15%.
Employment insurance: about 0.6%.
(Child‑care contribution etc. is generally employer‑side in this simplified model.)
Total employee social insurance: roughly 14.8% of gross salary.
Thus, at the same nominal gross salary, Japan’s employee social insurance burden is about 5 percentage points higher than Korea’s.
3. Impact on net income
Because both:
the effective tax (income + local/resident) is a bit higher in Japan, and
the social insurance rate is significantly higher in Japan,
the net (after‑tax, after‑insurance) income is higher in Korea, and the gap widens as salary increases:
At 50M KRW: Korea net is higher by about 3.24M KRW.
At 100M KRW: Korea net is higher by about 6.13M KRW.
At 200M KRW: Korea net is higher by about 11.32M KRW.
If you want, a next step could be to re‑run this with a specific, current KRW‑JPY exchange rate and more precise Japanese deduction rules for a particular prefecture/municipality.
