Mio doesn't guess — she does the arithmetic. Enter your annual gross salary (the figure on your contract, before anything is taken out) and Mio estimates each deduction and your real net pay. It's an estimate, not your exact payslip — real rates shift by prefecture, health-insurance society, dependents and year — but it gets you in the right neighbourhood.
Assumes a company employee on Shakai Hoken (社会保険). If you're self-employed or on National Health Insurance (国民健康保険) + National Pension (国民年金), your numbers differ — see the resident-tax guide. Single filer, no extra dependents assumed.
| Deduction (estimate) | Per year | Per month |
|---|
Resident tax is shown for reference — remember it's billed the FOLLOWING year based on this year's income, so in your first year in Japan you typically don't pay it yet (and it keeps coming after you stop working).
Take-home feels thin? Don't chase a raise first — the fastest, guaranteed wins are your fixed costs. See Mio's cheap-SIM / MNP cashback breakdown and the payslip guide to find money you're already losing every month.
Mio reads the Japanese-language official tiers and applies them in order — the same steps a year-end adjustment (年末調整) roughly follows:
| Step | What it does (illustrative rates) |
|---|---|
| Health insurance (健康保険) | ≈ 5.0% of gross under 40; ≈ 5.9% at 40+ (adds long-term care). Employer pays a matching share. Varies by prefecture/society. |
| Employees' pension (厚生年金) | 9.15% of gross, capped above a standard monthly remuneration of ~¥650,000 (so contributions flatten past roughly ¥7.8M/yr). |
| Employment insurance (雇用保険) | ≈ 0.6% of gross (employee share; varies by industry/year). |
| Income tax (所得税) | Gross − employment-income deduction − social insurance − basic deduction (~¥480k) = taxable income. Then national brackets 5/10/20/23/33/40/45% + 2.1% reconstruction surtax. |
| Resident tax (住民税) | ≈ 10% of a similar taxable base + ~¥5,000 flat (per-capita). Billed the next year. |
Mio uses the 2020+ employment-income-deduction tiers (¥650k minimum) and a ~¥480k basic deduction as an illustrative baseline. Japan's 2025 reform is raising the basic and minimum deductions, and resident-tax deductions differ slightly from national ones — so treat the tax lines as ballpark, not to-the-yen.
Two things trip up newcomers most. First, resident tax lag: it's charged in the year after you earn, so your second year can feel tighter than your first even on the same salary — and it can arrive after you've already left a job. Second, the bonus effect: a big annual bonus is taxed and charged social insurance too, so your monthly average and your bonus-month take-home look very different.