利息計算機
単利または複利で最終金額と利息を求めます。複利は年・半年・四半期・月・日ごとから選べます。
結果
値を入力して「計算」を押すと結果が表示されます。
公式
Simple interest: principal × yearly rate (as a decimal) × years.
Compound interest: the rate is split over n periods a year, and interest earns interest.
この計算ツールの使い方
- Choose simple or compound interest and enter the starting amount, the yearly rate in % and the time in years.
- For compound interest, choose how often interest is added. Money is shown to 2 decimal places.
解き方付き例題
1000 at 5% a year for 3 years, compounded yearly
r = 5% = 0.05, n = 1 and nt = 3.
A = 1000 × 1.05³ = 1157.625, which rounds to 1157.63.
Interest = 1157.63 − 1000 = 157.63; the effective annual rate is exactly 5%.
よくある質問
What is the difference between simple and compound interest?
Simple interest is only paid on the starting amount. Compound interest is also paid on interest already added, so it grows faster.
What is the effective annual rate?
The rate you really earn in a year once compounding is included — also called the APY. Monthly compounding at 5% gives about 5.1162%.