Enter初始投资金额
年利率、期限、Compounding Frequency
查看本息总额和Year-by-Year Breakdown
Calculate存款/投资的复利收益
Calculate基金定投的长期收益
Calculate复利收益，支持按月/Annually
Compound interest is the most powerful force in finance — it is interest earned on both your original investment and on the interest that investment has already accumulated. Albert Einstein reportedly called it the "eighth wonder of the world." Understanding how compound interest works is the foundation of all smart investing and saving decisions.
Simple interest only earns on the original principal. Formula: Total = Principal × (1 + Rate × Years).
Compound interest earns on principal plus accumulated interest. Formula: Total = Principal × (1 + Rate/n)^(n × Years).
With $10,000 at 5% over 10 years: simple interest gives you $15,000, but compound interest gives you $16,289 — nearly $1,300 more. Over 30 years, the gap widens to over $18,000 ($25,000 vs. $43,219).
More frequent compounding = higher returns, because your interest starts earning interest sooner:
With $10,000 at 5% for 10 years: annual compounding yields $16,289, monthly yields $16,470, daily yields $16,487. The difference is modest for short periods but becomes significant over decades.
A quick mental math shortcut: Years to double ≈ 72 ÷ Interest Rate. At 6% annual return, your money doubles in roughly 12 years. At 8%, it doubles in about 9 years. At 12%, just 6 years. This approximation works best for rates between 6% and 12%.
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