iDeCo Tax Savings Calculator

iDeCo (individual-type Defined Contribution pension plan) contributions are fully deductible as small enterprise mutual aid contribution deductions from your taxable income, resulting in reduced income tax for that year and resident tax for the following year. This calculator lets you easily estimate your annual tax savings.

The tool supports six employment types, each with different contribution limits: company employees without corporate pensions (23,000 yen/month), employees with corporate DC plans (20,000 yen/month), employees with DB plans (12,000 yen/month), public servants (12,000 yen/month), self-employed individuals (68,000 yen/month), and homemakers (23,000 yen/month). Your taxable income is calculated by subtracting salary income deduction, social insurance premiums, and the basic deduction from your annual income. Tax savings are then computed using your marginal income tax rate (5%-45% progressive rates), reconstruction special income tax (2.1%), and resident tax rate (10%).

The calculator also displays cumulative tax savings over 10, 20, 30 years, and until retirement age to help with long-term financial planning. All calculations run entirely in your browser with no data transmitted externally. *Results are estimates only. Actual savings vary by individual deductions and social insurance status. Consult a tax professional for precise amounts.