📊 储蓄计划

📐 计算公式与说明

达成时间(月) N = log(1 + 目标×月利率 ÷ 月存) ÷ log(1 + 月利率)
(若有初始存款,公式需用对数迭代求解)
演算示例(目标10万,已有1万,月存3千,年利率2%) 月利率 = 2% ÷ 12 ≈ 0.1667%
每月连本带利累积,约需 28.4 个月(约2年4个月)
届时本息合计约 ¥101,500

📌 利率对存款目标影响大吗?

短期(1-2年)影响很小,但长期(5年以上)复利效应显著。例如月存5000元、年利率3%,10年后比0利率多出约8万元利息。中国目前货币基金收益率约2%,美国高收益储蓄账户约4%。

📌 如果想提前达成目标,每月需要多存多少?

您可以在“每月计划存入”中调整金额,观察达成时间的变化。也可以用本计算器反向测试:先设定期望的达成月数,再手动调节月存金额,直到达成时间与期望相近。

📌 中美储蓄工具有什么不同?

中国常见的储蓄工具包括银行定期存款、零存整取、货币基金(余额宝);美国主要有高收益储蓄账户(HYSA)、定期存单(CD)。本计算器使用的复利公式全球通用,您只需输入对应的年利率即可。

📊 Savings Plan

📐 Formulas & Notes

Time to Goal (months) N = log(1 + Goal × r ÷ Deposit) ÷ log(1 + r)
(With initial savings, an iterative logarithmic formula is used)
Example ($100k goal, $10k saved, $3k/month, 4% rate) Monthly rate = 4% ÷ 12 ≈ 0.3333%
Compounding monthly, goal reached in ~27.3 months (~2 years 3 months)
Final balance ≈ $100,500

📌 How much does interest rate matter?

Minimal for short terms (1-2 years), but significant over 5+ years. Saving $500/month at 4% vs 0% yields ~$7,000 extra over 10 years. Current U.S. HYSA rates are around 4%, China's money market funds around 2%.

📌 How to speed up my goal?

Adjust the "Monthly Deposit" input to see how much sooner you'd reach your target. You can also manually test: pick your desired timeline, then tweak the monthly deposit until the calculated time matches.