Japan · 2026
iDeCo tax savings calculator
iDeCo 節税額 シミュレーション
Enter your salary and monthly contribution to see how much income tax and resident tax iDeCo saves you each year, and what the saving really costs you.
Tax you save each year (節税額)
¥51,964
19% of the ¥276,000 you put in comes back as lower tax, so saving it really costs you ¥224,036.
- Less income tax (所得税)
- ¥24,364
- Less resident tax, next year (住民税)
- ¥27,600
Tax saved on ¥23,000 a month (月2.3万円の節税額)
¥276,000 a year, single, Tokyo.
| Salary | Tax saved a year | Real cost |
|---|---|---|
| ¥3,000,000 | ¥41,690 | ¥234,310 |
| ¥4,000,000 | ¥41,690 | ¥234,310 |
| ¥5,000,000 | ¥51,964 | ¥224,036 |
| ¥6,000,000 | ¥55,780 | ¥220,220 |
| ¥8,000,000 | ¥83,959 | ¥192,041 |
| ¥10,000,000 | ¥83,959 | ¥192,041 |
Questions
How does iDeCo save tax?
Everything you pay into iDeCo is deducted from your income (小規模企業共済等掛金控除) for both income tax and resident tax. You save your marginal income tax rate plus 10% resident tax on every yen you contribute: about 15% at lower salaries, 20% on a middle salary and 30% or more on a high one.
How much can an employee contribute to iDeCo?
In 2026, ¥23,000 a month with no company pension, and ¥20,000 a month (less any company DC contributions) with a company pension. From January 2027's contributions, the limit for employees becomes ¥62,000 a month including any company DC contributions.
When do I see the saving?
Income tax comes back through the year-end adjustment (年末調整) if contributions come out of your salary or you submit the certificate to your employer. The resident tax saving shows up as lower resident tax from the following June.
Is there a catch?
The money is locked until age 60, and you pay tax when you withdraw it, though lump sums and pensions get generous deductions of their own. Account fees run a few hundred yen a month.