Project the future value of an investment that starts with a lump sum and grows with monthly contributions at a fixed annual return. The results break the final value into "money you put in" versus "growth" so the power of compounding is visible.
Returns are compounded monthly and shown year by year. Real-world returns vary — this is a planning tool, not a promise — but it makes the trade-off between contribution size and time horizon concrete.
Frequently asked questions
What return rate should I use?
Historically broad stock indexes returned about 7–10% per year before inflation; use a conservative number for planning.
Does it account for inflation?
No — enter a real (inflation-adjusted) return rate if you want results in today's purchasing power.
When do contributions happen?
At the end of each month, and they start earning returns the following month.
中文说明
预测一笔投资的未来价值：起始一次性投入 + 每月定投，按固定年收益率复利增长。结果把终值拆分为"投入本金"与"收益增长"两部分，复利的力量一目了然。
收益按月复利计算并逐年展示。实际收益会有波动——这是规划工具而非承诺——但它能直观呈现定投金额与投资期限之间的权衡。
常见问题
收益率应该填多少？
历史上宽基股指的年化收益约为 7–10%（未扣通胀）；做规划时建议使用更保守的数字。
考虑通货膨胀吗？
不考虑。若想按今天的购买力查看结果，请输入扣除通胀后的实际收益率。
定投是什么时候计入的？
每月月末计入，从下个月开始产生收益。