About Compound Interest Calculator

Projects the future value of an investment with compound interest and recurring monthly contributions. Supports five compounding frequencies—annual, quarterly, monthly, weekly, and daily. Results update live as you adjust inputs, with quick presets for common investment scenarios.

• Uses the standard compound interest formula: A = P(1 + r/n)^(nt) plus future value of annuity for contributions
• Five compounding frequencies: annually (1), quarterly (4), monthly (12), weekly (52), daily (365)
• Monthly contribution treated as an annuity with the same compounding frequency
• Three quick presets: Balanced ($10k/8%/10yr), Conservative ($25k/6%/12yr), Aggressive ($5k/10%/5yr)
• Copy results as formatted text or export full calculation as JSON

Frequently Asked Questions

Does compounding frequency make a big difference?

Less than you’d think. Going from annual to daily compounding on $10,000 at 7% over 10 years adds roughly $60. Monthly contributions have a far larger impact on final value than compounding frequency.

Does this account for taxes or inflation?

No. The calculation shows nominal future value. For real (inflation-adjusted) returns, subtract your expected inflation rate from the annual rate before entering it.