Tax Simulators: Reform Impact, iDeCo Tax Savings & the Dependent-Income Thresholds, all on one page
We have gathered our three tax simulators onto a single page. Switch between the tabs to instantly estimate how much your take-home pay changes under the tax reform, how much you can save in tax with iDeCo, and how your take-home pay changes across the dependent-income thresholds (¥1.06M / ¥1.30M / ¥1.60M). Everything is free, no registration required, and your input data is not sent to any server.
Standalone pages: Tax Reform / iDeCo Tax Saving / Dependent-Income Thresholds ※ Each simulator can also be embedded in blogs and elsewhere for free.
What each simulator tells you
Tax Reform Simulator——With the basic deduction and employment income deduction raised under the reform applying from 2026 (Reiwa 8), it compares how much your income tax, residence tax and take-home pay change before and after the reform.
iDeCo Tax-Saving Simulator——From your monthly contribution and annual income, it estimates the reduction in income tax and residence tax and your cumulative savings. Read it alongside how iDeCo saves tax.
Dependent-Income Threshold Simulator——It charts how your take-home pay changes as you move the annual income of a part-time or arubaito worker. It helps you understand the ¥1.06M and ¥1.30M thresholds and the residence-tax exemption line.