Free Japanese Tax & Finance Calculators
For foreign residents in Japan and anyone needing to calculate Japanese income tax, pension, residence tax, mortgage, NHI, and 700+ other daily-life numbers. All free, no signup, in your browser only.
Top 20 calculators for residents in Japan
The Japanese-language form is the source of truth for now; an English UI is in progress. The link below opens the Japanese page — most fields use international numbers and the result is universal.
Income Tax
Japanese income tax for residents.
OpenResidence Tax
Local prefecture & city tax.
OpenNational Health Insurance (NHI)
Self-employed / part-time worker NHI premium.
OpenNational Pension
Kokumin Nenkin monthly contribution.
OpenTake-Home Pay
Net pay from gross salary in Japan.
OpenMortgage Monthly Payment
Japanese housing loan calculator.
OpenMortgage Tax Deduction
Jutaku loan kojo benefit.
OpenFurusato Nozei Limit
Hometown tax donation cap.
OpeniDeCo Tax Saving
iDeCo contribution and tax benefit.
OpenNew NISA Simulation
2024+ NISA non-taxable investment.
OpenInheritance Tax
Sōzokuzei calculation.
OpenGift Tax
Zōyozei annual gift tax.
OpenPension Estimator
Estimated kōsei + kokumin pension.
OpenRetirement Allowance Tax
Taishokukin tax deduction.
OpenProperty Tax (固定資産税)
Annual property tax estimate.
OpenBMI
Body Mass Index.
OpenDaily Calorie
Daily calorie needs.
OpenAffordable Rent
Recommended rent based on take-home pay.
OpenMoving Cost
Cost of moving in Japan.
OpenJPY to USD
Currency conversion.
OpenLooking for a specific calculator that isn't listed? Browse all 709 tools or use the search box at the top right.
Why Keisan Tools?
- No signup, no loginEverything runs in your browser. Favorites and history are stored locally — never on a server.
- 2026 tax-year compliantUpdated for the latest NTA brackets, NHI rates, and pension contribution amounts.
- Designed for residents in JapanMost online calculators in English are US/UK biased. Ours follows Japanese rules end-to-end.
- Mobile-first, accessibility-firstLarge fonts, high contrast, voice input — all available from the accessibility button.
⚠️ Disclaimer: These calculators are estimates. For actual tax filing, please consult a licensed 税理士 (zeirishi) or FP (financial planner). Results are not a substitute for professional advice.