What is compound interest?

Compound interest is interest calculated on both the initial principal and the accumulated interest from previous periods. It's the mechanism that makes money grow non-linearly over time — earnings earn earnings.

How is it different from simple interest?

Simple interest is calculated only on the original principal (Interest = P × r × t). Compound interest reinvests each period's interest, so the balance grows at an accelerating rate. Over long horizons the gap is dramatic.

What does compounding frequency change?

It's the number of times per year interest is added to the balance. More frequent compounding produces slightly higher growth at the same nominal rate — but the marginal benefit shrinks fast as frequency increases. Monthly is meaningfully better than annual; daily is barely better than monthly.

What is continuous compounding?

The mathematical limit of compounding infinitely often, given by A = P × e^(r·t) where e ≈ 2.71828. It sets an upper bound on what any other compounding schedule can produce at the same rate.

How do I use this calculator?

Enter the principal (starting amount), the annual interest rate as a percentage, the time in years, and pick a compounding frequency. The final amount and total interest earned appear instantly.

Does this account for taxes, fees, or contributions?

No. This is a pure compound-interest projection. Real investments involve taxes, fees, inflation, and (for savings goals) periodic contributions — all of which a richer financial-planning calculator would model.

复利计算器 — 终值与复利频率

复利计算器

FAQs

What is compound interest?: Compound interest is interest calculated on both the initial principal and the accumulated interest from previous periods. It's the mechanism that makes money grow non-linearly over time — earnings earn earnings.
How is it different from simple interest?: Simple interest is calculated only on the original principal (Interest = P × r × t). Compound interest reinvests each period's interest, so the balance grows at an accelerating rate. Over long horizons the gap is dramatic.
What does compounding frequency change?: It's the number of times per year interest is added to the balance. More frequent compounding produces slightly higher growth at the same nominal rate — but the marginal benefit shrinks fast as frequency increases. Monthly is meaningfully better than annual; daily is barely better than monthly.
What is continuous compounding?: The mathematical limit of compounding infinitely often, given by A = P × e^(r·t) where e ≈ 2.71828. It sets an upper bound on what any other compounding schedule can produce at the same rate.
How do I use this calculator?: Enter the principal (starting amount), the annual interest rate as a percentage, the time in years, and pick a compounding frequency. The final amount and total interest earned appear instantly.
Does this account for taxes, fees, or contributions?: No. This is a pure compound-interest projection. Real investments involve taxes, fees, inflation, and (for savings goals) periodic contributions — all of which a richer financial-planning calculator would model.

什么是复利？

复利是同时按本金以及之前各期累计利息计算的利息。与只按本金计算的单利不同，复利将每期收益再投资，因此余额随时间呈非线性增长。这正是长期储蓄、退休账户和再投资股息能远远超过短期线性预测的原因。

复利公式

A = P × (1 + r/n)^n·t

其中 A 为最终金额，P 为本金，r 为年利率（小数形式），n 为每年复利次数，t 为年限。

对于连续复利（n → ∞）：A = P × e^r·t，其中 e ≈ 2.71828。

计算示例

您以年利率 5% 存入 ¥1,000，按月复利，期限 10 年：

A = 1000 × (1 + 0.05/12)^12·10 ≈ ¥1,647.01

获得利息 ¥647.01。如果改为连续复利，结果是 ¥1,648.72，仅多 ¥1.71。

复利频率

频率	n（每年期数）	示例：¥1,000 按 5% 计 10 年
每年	1	¥1,628.89
每半年	2	¥1,638.62
每季	4	¥1,643.62
每月	12	¥1,647.01
每周	52	¥1,648.33
每日	365	¥1,648.66
连续	∞	¥1,648.72

如何使用本计算器

输入本金。
输入年利率（百分比），例如 5 表示 5%。
输入年限。
选择复利频率。
最终金额与利息总额立即显示。

局限性

无定期投入。本计算器仅模拟一次性本金。
未计税。实际利息收入通常需缴税。
未计通胀。结果为名义金额。
利率恒定。实际利率会变动。
未计费用。账户或基金费用未模拟。

如需个人理财规划，请咨询专业财务顾问。