自動車ローンの実質年率を計算
月々の返済額から自動車ローンの実質年率を計算できます。残価設定ローンの場合は、最終回の残価を入力してください。ディーラーローンと銀行のマイカーローンの比較にも使えます。
計算機は英語表示です。ブラウザの翻訳機能でワンクリックで日本語に切り替えられます。
Car loan rules in Japan
- Under the Installment Sales Act (割賦販売法), dealer car loans must show the real annual rate (実質年率), calculated on the declining balance. Bank auto loans are usually cheaper than dealer loans.
- Residual-value loans (残価設定ローン) are common. You pay down only part of the price, then pay the residual, refinance it, or hand the car back at the end. Bonus-month payments (ボーナス払い) are also common; this calculator assumes equal monthly payments.
- Most Japanese car loans let you repay early free or for a small flat handling fee (繰上げ返済手数料). For example, MUFG’s car loan is free online and ¥5,500 at a branch.
Sources: Japan FSA: 実質年率 explained · MUFG car loan repayment. Rules checked October 2026.
How to use this calculator
Choose Find my APR and enter the price, your down payment, the term and the monthly payment from your offer. The calculator works backward to the APR that lenders in Japan must disclose, and shows the same loan as a nominal rate and an effective rate. Choose Find my payment to turn a quoted rate into a monthly payment. All figures are in JPY and you can switch country at the top of the page.
Frequently asked questions
What is 実質年率?
It is the real annual rate Japanese dealer loans must show under the Installment Sales Act, calculated on the declining balance and including fees.
How do residual-value loans work?
You pay off part of the price monthly and leave a residual (残価) as the final payment, which you pay, refinance or settle by returning the car.
実質年率とは何ですか？
手数料を含めたローンの年間コストを、残高に対する年率で示したものです。割賦販売法により、ディーラーローンでは表示が義務づけられています。
残価設定ローンの返済額はどう計算しますか？
車両価格から頭金と残価を除いた分を月々払い、最終回に残価を支払います。残価を「最終回の支払い」欄に入力すると計算できます。