iDeCo Tax-Saving Simulator | How much do taxes drop if you do (or skip) it?

iDeCo (individual defined contribution pension) contributions are fully deductible from income (small-scale enterprise mutual-aid contribution deduction), which lowers your income tax and residence tax by that amount. Just enter your annual income and monthly contribution to estimate the tax difference between "not doing it" and "doing it" — your annual tax saving. No sign-up required; your inputs are not transmitted and everything is calculated only on your device, with the full calculation shown (estimate).

* This tool is an estimate for general information only and is not tax or investment advice. It assumes you are single, have no dependents, and claim no other income deductions; for employees and public servants, social insurance premiums are estimated at about 15% of annual income. The tax saving is the reduction in income tax (including the reconstruction surtax) and residence tax (10%) from fully deducting the contributions from income. Note that iDeCo funds generally cannot be withdrawn until age 60 and are taxed on receipt (subject to the retirement income deduction and the public pension deduction), and that investment gains or losses may arise. For details on contribution caps and eligibility, check the official iDeCo site (in Japanese).