Compound interest is interest earned on interest: each period, gains join the principal and the next cycle compounds on the new total. This calculator projects future wealth from starting principal, annual return, compounding frequency, and regular monthly contributions.
The formula is A = P·(1 + r/n)^(n·t) plus accumulated monthly cash flows. Over 10 to 30 years, compound interest transforms modest monthly investments into substantial fortunes.
Frequently asked questions
What is the difference between simple and compound interest?
Simple interest only pays on original principal; compound interest pays on principal plus accumulated interest.
Does compounding frequency matter?
Yes. More frequent compounding (e.g. monthly vs annually) produces slightly higher overall returns.
Are monthly contributions added at the start or end of the month?
Added at the end of each month and start compounding in the following period.
中文说明
复利是财富积累的核心杠杆：每期收益并入本金，下一期继续利滚利。本计算器支持初始本金、预期年化收益率、复利频率与每月定投金额，完整预测资产增长轨迹。
长期定投结合复利效应，能将每月几百或几千元的小额结余转化为数倍乃至十倍以上的终身财富。
常见问题
单利与复利有什么区别？
单利永远只按初始本金计息；复利按不断滚存的总资产计息，即"利生利、利滚利"。
复利计息频率有影响吗？
有影响。按月复利或按日复利比按年复利收益略高，时间越长差异越明显。
每月定投从什么时候开始计息？
定投在每月月末投入，从下个月开始计入复利池产生收益。