Free Finance Tools for Expats in Japan

What We Offer

Free tools plus educational content covering Japanese finance, customs, and expat life:

Learn & Explore

Beyond calculators, we publish articles and guides to help you navigate the financial and cultural landscape of Japan.

Why Trust YenWise

Editorial standards

YenWise content is produced by the YenWise Editorial team for expats navigating Japanese tax, pensions, investing, housing, and residency rules. We prioritize primary public sources, clear assumptions, and review dates on tools and articles.

We are not a tax office, immigration bureau, or licensed advisory firm. Our role is educational software and explainers. When your case is high-stakes, use our outputs as a structured brief for a zeirishi, FP, or immigration professional.

Corrections and methodology questions are welcome via the contact address on this page. When we change a formula, we aim to update the tool review date and related article copy together.

Our Methodology

Every calculation on YenWise is built from the ground up using primary sources. We do not estimate or approximate unless clearly stated. Tax brackets, deduction formulas, pension coefficients, and social insurance rates are all traced to specific NTA bulletins (国税庁タックスアンサー), FSA publications, or Japan Pension Service (日本年金機構) documentation.

When the 2026 Reiwa 7 tax reform changed how basic deductions work, we rebuilt our entire income tax engine from scratch. The two-track system — where national income tax uses a dynamic deduction scale while residence tax retains legacy flat rates — is fully implemented. Truncation rules (切り捨て) required by the General Law of National Tax (国税通則法) are applied at every step.

We treat transparency as a feature, not a limitation. Each result page explains which figures are exact, which are statutory estimates, and which are approximations — and why. Where a calculation depends on an assumption (for example, the expected investment return in the NISA calculator, or the average monthly salary in the pension calculator), the assumption is always user-controlled and clearly labeled. We never hide a parameter behind a "black box." If a number on your screen does not match your real-life document, you can trace exactly which input or rule produced it.

Your Data Stays on Your Device

Privacy is not an afterthought on YenWise — it is the default architecture. Every calculator runs entirely in your browser using JavaScript, which means your salary, investment amounts, pension details, and any other numbers you enter never travel to our server, are never written to a database, and disappear the moment you close the tab. We have no accounts, no login, and no way to tie a calculation to a person. The only data we collect is anonymous, aggregated page-view analytics so we can see which tools are useful and fix the ones that are not. You can verify this yourself with your browser's network inspector: unlike most finance sites, you will not see your inputs leave the page.

Who This Is For

YenWise is built for the people who fall through the cracks of most Japanese finance resources — fluent enough to live and work here, but not always equipped to decode a tax notice written for native speakers. The tools below cover the full range of users we have in mind, from someone on their first working holiday visa to a long-term resident optimizing a retirement portfolio. Whoever you are, the goal is the same: turn opaque Japanese paperwork into a number you can actually act on.

• ✓Expats working in Japan who want to understand their taxes and take-home pay
• ✓People planning to move to Japan who need to budget for taxes and living costs
• ✓Long-term residents managing NISA, iDeCo, and Furusato Nozei contributions
• ✓Expats and residents researching Japanese finance, taxes, and customs who want clear, accurate explanations
• ✓日本語話者の方もどうぞ — すべてのツールは日本語に対応しています