NISA Investment Simulator

Fully supports Japan's new NISA system. Accurately simulates with Tsumitate quota (1.2M/yr), Growth quota (2.4M/yr), and lifetime cap (18M yen). Shows tax-free advantage amount, asset growth chart, and yearly breakdown.

Last updated: 2026/03/01 Finance
Fully supports Japan's new NISA system (started 2024). Accurately reflects Tsumitate and Growth investment quota limits.
Tsumitate (Regular Savings) Quota
yen/mo
Growth Investment Quota
yen/mo
yen
%
Reference rates
years
Final Assets
0M yen
Total Gain
0M yen
Total Principal
0M yen
Tax-Free Advantage
0M yen
vs. Taxable Account
Lifetime Investment Quota Usage
0万円 / 1,800万円(0%)
Tsumitate Quota: 0万円 Growth Quota: 0万円

Asset Growth Simulation

Yearly Simulation Details
Year Tsumitate Growth Principal Gain Total Taxable Tax Savings

※ This simulation provides estimates only and does not guarantee actual investment results.

※ Investments involve risk. All investment decisions are your own responsibility.

※ Taxable accounts are calculated at 20.315% (income tax 15% + reconstruction tax 0.315% + resident tax 5%). The reconstruction tax applies through the end of 2037.

※ Expected returns are based on historical averages and do not guarantee future performance.

How to Use

1

Set Investment Amounts

Set monthly investment for Tsumitate and Growth quotas using sliders or number inputs. You can also set an initial lump-sum for the Growth quota.

2

Set Return Rate & Period

Choose an expected return rate from presets (Global Equity 5.0%, S&P500 7.0%, etc.) or enter custom values. Set the investment period from 1 to 50 years.

3

Review Simulation Results

Results update in real-time as you change inputs. Review final assets, tax-free advantage, asset growth chart, and yearly breakdown table.

About NISA Simulator

A comprehensive investment simulator for Japan's new NISA (Nippon Individual Savings Account) tax-free investment program started in 2024. Accurately reflects the Tsumitate quota (1.2M yen/year), Growth quota (2.4M yen/year), and lifetime cap (18M yen, of which Growth is limited to 12M). Shows concrete tax-free advantage amounts, beautiful asset growth charts, and detailed yearly projections. All calculations run in your browser.

Features

  • Full New NISA SupportReflects all quota limits: Tsumitate (1.2M/yr), Growth (2.4M/yr), Lifetime (18M yen). Accurate, system-compliant simulation.
  • Tax-Free Advantage DisplayShows concrete savings compared to a taxable account (20.315% tax). See exactly how much you benefit from NISA's tax exemption.
  • Real-time Charts & TablesResults, charts, and tables update instantly as you change inputs. Stacked bar chart shows principal and gain breakdown.
  • Lifetime Quota ProgressProgress bar shows usage of the 18M yen lifetime quota. Auto-calculates the year when the quota is fully used.

Use Cases

  • Planning investments before starting NISA
  • Comparing final assets with different monthly amounts
  • Checking how much you save with NISA tax exemption
  • Finding how many years to fully use the 18M yen quota
  • Deciding allocation between Tsumitate and Growth quotas

FAQ

What is Japan's new NISA system?
NISA (Nippon Individual Savings Account) is Japan's tax-free investment program started in 2024. It has two quotas: Tsumitate (1.2M yen/year for index funds) and Growth (2.4M yen/year for stocks and funds). The lifetime cap is 18M yen (Growth limited to 12M). Investment gains are tax-free indefinitely.
What return rate should I use?
Historical long-term averages: Global equity index ~5%, S&P500 ~7%. These are not guaranteed. For conservative estimates, use 3-5%.
How is the tax-free advantage calculated?
NISA gains are tax-free, while regular accounts are taxed at 20.315%. The advantage is the difference between NISA and taxable account final values, compounded annually.
What happens when the 18M yen lifetime cap is reached?
No new investments can be made, but existing assets continue to grow tax-free. Sold positions restore the quota the following year (not simulated in this tool).
What's the difference between Tsumitate and Growth quotas?
Tsumitate (1.2M/yr) is for selected index funds only. Growth (2.4M/yr, lifetime max 12M) allows stocks and broader fund selection.
What are the monthly investment limits?
Tsumitate: 100,000 yen/month (1.2M/yr). Growth: 200,000 yen/month (2.4M/yr). Combined maximum: 300,000 yen/month (3.6M/yr).
Are the calculations accurate?
All NISA quota limits are accurately reflected. Returns assume a constant annual rate; actual results vary with market conditions. Use as a reference only.
Does this work on smartphones?
Yes, fully responsive design with touch-friendly sliders.
Is my data sent to any server?
No, all calculations happen in your browser. No data is transmitted.
How does this differ from the old NISA?
The new NISA (2024~) has unlimited tax-free period (old: 5/20 years), larger quotas, and a 18M yen lifetime cap. This tool simulates the new system only.