How this is calculated
The calculator models a full-time employee on the government-run health insurance most smaller and mid-sized companies use (Kyokai Kenpo), enrolled in Employees' Pension, paid the same salary every month. These are the rates it uses, all checked against the official sources on 22 October 2026.
- Health insurance: your prefecture's Kyokai Kenpo rate, split 50/50 with your employer. Tokyo is 9.85% for the year from March 2026. If you are 40 to 64, nursing care insurance adds 1.62%.
- Child and child-rearing support levy: a new 0.23% charge collected with health insurance from the April 2026 premium, also split 50/50.
- Employees' Pension: 18.3%, split 50/50, so 9.15% from you.
- How those are applied: insurance is charged on a standard monthly remuneration grade rather than your exact pay. Pension stops rising at the ¥650,000 grade; health insurance goes up to ¥1,390,000. Your half is rounded to the yen the way payroll does it.
- Employment insurance: 0.5% of your pay (the employee rate for most businesses from April 2026 to March 2027).
- Income tax: national rates from 5% to 45%, plus the 2.1% reconstruction surtax. It uses the 2026 employment income deduction (now at least ¥740,000) and the 2026 basic deduction, which is ¥1,040,000 for total income up to ¥4.89 million, ¥670,000 up to ¥6.55 million and ¥620,000 above that. Social insurance is deducted in full. The result is the annual figure after your December year-end adjustment.
- Resident tax: 10% of taxable income (4% prefectural and 6% municipal), after a ¥430,000 basic deduction and the adjustment credit, plus Tokyo's ¥5,000 per-capita charge.
- Dependants: a spouse with little or no income is worth ¥380,000 off income tax and ¥330,000 off resident tax (less above ¥9 million of income). Each dependant aged 16 or over is the same; dependants aged 19 to 22 are worth ¥630,000 and ¥450,000.
What it leaves out
- Bonuses. Insurance on bonuses is charged separately, so a salary with large bonuses will come out slightly differently.
- Commuting allowance. It is usually tax-free but still counts for social insurance, so it raises your insurance a little without changing your tax.
- Company health insurance societies (kenpo kumiai) set their own rates, often lower than Kyokai Kenpo.
- Children under 16, disabled dependants, life insurance, iDeCo and other deductions, which all lower your tax.
- Your local per-capita charge and any local tax-free thresholds. Most cities are close to Tokyo's ¥5,000, but low earners with several dependants may owe less resident tax than shown.
When each deduction actually happens
Insurance and income tax come out of every payslip from your first month. Income tax is withheld from a monthly table and then settled in the year-end adjustment with your November or December pay, which is why December's payslip often looks different.
Resident tax works on a delay. It is charged by the municipality where you live on 1 January, on the previous year's income, and taken from your pay from June to the following May. If you arrived this year you will usually pay little or none until next June, and then your take-home pay drops. Our resident tax and year-end adjustment guide explains the timing, and the payslip guide shows where each of these lines appears.
Most employees never file a tax return. You do need to file between mid-February and mid-March if your salary is over ¥20 million, you have more than ¥200,000 of side income, or you want to claim something your employer cannot, such as medical expenses or furusato nozei donations to more than five places.
Where these numbers come from
- Kyokai Kenpo: 2026 health insurance rates by prefecture
- Kyokai Kenpo: 2026 Tokyo premium table (grades, nursing care, rounding)
- Kyokai Kenpo: child and child-rearing support levy (0.23%)
- Ministry of Health, Labour and Welfare: 2026 employment insurance rates
- National Tax Agency: income tax rates (No.2260)
- National Tax Agency: 2026 changes to the basic and employment income deductions
- Ministry of Internal Affairs and Communications: resident tax basic deduction and 2026 reform
- Tokyo Metropolitan Government: resident tax rates and per-capita levy
Rates are dated rather than undated: last checked 22 October 2026. This is an estimate, not tax advice — confirm anything consequential with your employer, your tax office or a tax accountant.