Income tax & the reconstruction surtax

Japanese income tax (所得税) is progressive, but you never read a marginal rate off your salary directly. The rate applies to your taxable income, which is what is left after two deductions carve into your gross pay — and the tax itself is worked out with a subtractive shortcut called the quick-calc table (速算表). This page walks through that chain and shows the table underneath.

The quick-calc table (速算表)

The table is a 7-tier progression running from a first-tier 5% up to a top-tier 45%. Rather than summing each band by hand, the statute gives one line per tier: tax = taxable income × rate − a subtractive deduction. That subtractive figure is exactly the arithmetic that would otherwise come from adding up the lower bands, folded into a single number — so a marginal progression is computed in one multiply-and-subtract. The table below is that 速算表 itself, read straight from the payload.

One rule matters before you apply it: taxable income is rounded down to the nearest ¥1,000 (課税所得の千円未満切捨て) first. A taxable income that should land on a round thousand and instead shows odd yen is a sign the rounding was skipped.

From gross to taxable income

Two deductions stand between your annual gross and the figure the table sees. First the employment-income deduction (給与所得控除) turns gross salary into “employment income” — its floor is ¥650,000 under the 2025 reform (the 令和7年分 table, in force for the 2026 (Reiwa 8) income-tax year). Then the basic deduction (基礎控除) and any dependent deductions come off to give taxable income; the basic deduction reaches up to ¥950,000 at lower incomes and tapers as income rises. Social-insurance premiums you actually paid are deductible here too, which is why the take-home calculator computes them first.

The employment-income deduction is written in the statute as a ¥4,000-step lookup table (所得税法別表第五) for lower incomes; this tool uses the smooth formula that approximates it, so a difference of a few hundred yen in the deduction can occur. That is disclosed, not hidden.

The reconstruction surtax (復興特別所得税)

Once the base national tax is found from the table, a 2.1% special reconstruction income tax is added on top of it, so the annual national tax is the base tax plus that surtax. It applies to every year from 2013 through 2037 and is a genuine part of what leaves your pay, not an optional extra.

The figures here are the rates in force for 2026: each cites a primary source (NTA タックス アンサー). Two things limit them: a very recent change may not have reached this page yet, and none has been signed off. For the amount that binds you, check with your employer or the National Tax Agency.