Student Part-Time Job Tax Calculator

An international student taking a part-time job at a café or restaurant in Korea usually has three questions at once: how much tax comes off the pay, whether social insurance applies, and whether a year-end settlement is required. Enter the hourly rate, the hours and days worked per week, and the number of months at the same employer, and this calculator shows the monthly pay, the tax withheld per day and per month, whether you join the social insurances, and whether you are in the year-end settlement.

Everything turns on whether you count as a day labourer. Fewer than 3 months with the same employer means day-labour income: tax is withheld per day worked and that is the end of it. 3 months or more of continuous employment makes you a regular employee, taxed from the standard payroll table and settled at year end. The same rate and the same hours can be taxed differently depending on how long you have been there, so the calculator takes the months first and decides which side you fall on.

Students about to start a part-time job who want a sense of what the first payslip will show. One thing comes before the tax, though. A student needs a part-time work permit before working, and working without one is not a tax problem but a breach of 출입국관리법. This calculator assumes you are working within the hours your permit allows and computes only tax and insurance. How many hours a week you are allowed depends on your visa, year of study, Korean proficiency and whether you are in term or on vacation; it sits in Ministry of Justice guidance rather than statute, so the page does not state a number. Confirm yours with Hi Korea or your school's international student office.

It also answers the student who has been at one job for a long time and wonders why no tax is being withheld, or why they have suddenly been told to do a year-end settlement. And it helps when an employer says they will withhold 3.3%: that is business-income withholding, not day-labour tax, which means the contract is of a different kind.

Whether you are a day labourer is set by 소득세법 시행령 제20조제1항제3호: outside construction and stevedoring, continuous employment with the same employer for 3 months or more takes you out of day-labour treatment. Day-labour tax is worked out per day. From the day's pay, subtract the employment income deduction of ₩150,000 under 소득세법 제47조제2항, multiply the remainder by 6% under 제129조제1항제4호 단서, and then credit back 55% of that under 제59조제3항. The net effect is 2.7% of whatever exceeds ₩150,000. If the income tax so calculated is below ₩1,000, 제86조제1호 says it is not collected at all; at ₩1,000 or more, local income tax of 10% is added and the sum withheld. Monthly tax is the daily tax times the number of days worked in a month.

Social insurance turns on 60 contracted hours a month. The calculator multiplies weekly hours by the average number of weeks in a month (365 ÷ 7 ÷ 12) to get monthly hours, and at 60 or more treats you as enrolled in the national pension at your workplace and covered by employment insurance (국민연금법 시행령 제2조제4호, 고용보험법 제10조제1항제2호). For health insurance, only a day labourer employed for under a month is excluded (국민건강보험법 제6조제2항제1호). Monthly pay is the hourly rate times monthly hours, without weekly holiday pay, overtime premiums or insurance contributions. Once you become a regular employee, tax follows the payroll table, so the calculator shows zero here and points you to the year-end settlement calculator.

The calculator's default is a student on the 2026 minimum wage of ₩10,320 an hour, working 15 hours a week over 3 days, in the second month at the same employer. Monthly hours are 15 times the average weeks per month, rounded to 65, and monthly pay is ₩10,320 times 65, or ₩670,800. Pay per day worked is 5 hours' worth, ₩51,600. After the ₩150,000 deduction nothing is left, so income tax is ₩0 and, under the small-amount rule, monthly tax is ₩0 as well. In the second month the student is a day labourer with no year-end settlement. At 65 hours a month, above the 60-hour line, social insurance applies.

At ₩20,000 an hour for 40 hours a week over 4 days the picture changes. Pay per day is ₩200,000, so ₩50,000 remains after the ₩150,000 deduction; 6% of that is ₩3,000, and crediting back 55% leaves ₩1,350 of income tax. That is at least ₩1,000, so 10% local income tax is added for ₩1,485 a day, and over a month's working days that comes to about ₩25,811. From monthly pay of ₩3,480,000 the student keeps ₩3,454,189. Leave the defaults alone but set the months to 3 and the result switches from day labourer to year-end settlement, with the tax box replaced by a note to use the payroll table.

The most dangerous mistake is working without a permit on the theory that paying tax properly is enough. The part-time work permit is separate from tax, and working without it is grounds for criminal penalties and deportation. The next most common is accepting "we withhold 3.3%" without question. That is business-income treatment, so neither the ₩150,000 daily deduction nor the 2.7% day-labour rate applies. If you were withheld as business income, you can settle and reclaim through the global income tax return the following May.

Many students who have worked at one place for more than 3 months still think of themselves as day labourers. From that point you are a regular employee in the year-end settlement, and because deductions then apply, it usually returns money rather than costing it, so there is no reason to avoid it. Believing that foreigners are exempt from social insurance is also wrong: at 60 hours a month or more you are enrolled regardless of nationality. The minimum wage applies to foreign workers in exactly the same way, and working 15 hours or more a week earns weekly holiday pay on top, so what you should actually receive may be more than the monthly pay shown here. If you work at more than one place, each job is calculated on its own.