¥400,000 a month after tax in Japan
Japanese pay talk runs on 月収 (monthly income), but the contract runs on bonuses: ¥400,000 a month is ¥4.8 million base, netting ¥309,708 a month — and with the typical twice-yearly bonus worth two months, the package becomes ¥5.6 million netting ¥4.29 million a year. Both versions below, because the gap between 月収 and 年収 is where Japanese salary confusion lives.
Base only vs base + 2-month bonus
| Item | Base ×12 (¥4.8M/yr) | + 2-month bonus (¥5.6M/yr) |
|---|---|---|
| Social insurance (~15.2%) | −¥730,560/yr | −¥852,320/yr |
| National income tax | −¥123,994/yr | −¥176,907/yr |
| Inhabitant tax (10%) | −¥228,944/yr | −¥280,768/yr |
| Net per year | ¥3,716,502 | ¥4,290,005 |
| Net per month (averaged over 12) | ¥309,708 | ¥357,500 |
Single filer under 40 (no long-term care premium), employment income deduction and social insurance deducted from the taxable base. Inhabitant tax is billed on the prior year's income — new arrivals in Japan famously enjoy one inhabitant-tax-free year, then meet the bill.
月収 vs 年収: always ask which one
Japanese recruiters quote 年収 (annual income, bonuses included); colleagues chat in 月収 (monthly base). A "¥400,000/month" job with a standard 2-month bonus is a ¥5.6M 年収 — but bonus months vary from 0 (many startups and foreign firms, who fold it into base) to 4–6 (large traditional firms and the civil service). Two offers with identical monthly figures can differ by over a million yen a year, which is why the only serious question in a Japanese salary negotiation is the annual number.
One more Japanese particular: taxes are gentle at this level (the effective rate is under 24%, lighter than nearly all of Europe) but the nenmatsu chosei year-end adjustment means most employees never file anything — the December payslip quietly settles the year. The system's real cost isn't the rate; it's the weak yen doing the damage in international terms, as our weak-yen analysis lays out.
Frequently asked questions
Base only: ¥309,708 net a month (¥3.72M/year). With a typical 2-month bonus the package is ¥5.6M gross, netting ¥4.29M — ¥357,500 a month averaged.
Above the national average — mid-career professional territory. ¥310,000 net covers a Tokyo one-bed (¥120,000–180,000 in the 23 wards) with reasonable margin, and lives generously in Osaka or Fukuoka.
As ordinary income — social insurance and withholding apply to bonus payments too. The June and December bonuses feel large because they're extra months, not because they're tax-advantaged.
Inhabitant tax (10%) is charged on the previous year's Japanese income — newcomers pay none in year one, then the bill starts in June of year two. Budget for the step.