以下のガイドはまだ日本語に翻訳されていないため、英語で表示しています。計算機自体はすべて日本語に対応しています。
この計算機の使い方
- Enter the amount you invested, including fees and costs.
- Enter the amount you received or the current value, including income such as dividends or rent.
- Enter how long you held the investment to see the annualized return.
計算式
Simple ROI ignores time. Annualized ROI (compound annual growth rate) converts the total return into an equivalent yearly rate.
ROI = (returned − invested) / invested × 100
Annualized ROI = (returned / invested)^(1/years) − 1
Example
- Invested $10,000, received $14,500 after 3 years.
- ROI = 4,500 / 10,000 = 45%.
- Annualized = 1.45^(1/3) − 1 ≈ 13.19% per year.
よくある質問
Why is annualized ROI lower than total ROI?
Total ROI accumulates over the whole holding period; annualized ROI spreads it across each year with compounding. A 45% gain over 3 years equals about 13.2% per year, not 15%.
Should I include costs?
Yes. Include purchase fees, commissions, taxes and maintenance in the invested amount (or subtract them from returns) for a realistic ROI.
What is a good ROI?
It depends on risk and alternatives. Compare it with what a low-risk option such as a savings account or government bond would have earned over the same period.