Daily Compound Interest Calculator
Calculate compound interest with daily compounding — the most aggressive standard frequency. High-yield savings accounts and most credit-card interest are computed daily.
Your Inputs
$
$
Future balance
Contributed
Interest earned
How to Use
1. Enter your initial investment — the lump sum you start with today.
2. Add your monthly contribution.
3. Set your expected annual return and time horizon with the sliders.
4. Choose how often interest compounds.
Results and the growth chart update instantly.
2. Add your monthly contribution.
3. Set your expected annual return and time horizon with the sliders.
4. Choose how often interest compounds.
Results and the growth chart update instantly.
Calculation Method
Future value of a lump sum plus a stream of monthly contributions:
FV = P(1 + r/n)^(nt) + PMT × [((1 + rm)^m − 1) / rm]
P = principal, PMT = monthly contribution, r = annual rate, n = compounds/year, rm = r/12, m = months, t = years. Returns are user-assumed and not guaranteed.
FV = P(1 + r/n)^(nt) + PMT × [((1 + rm)^m − 1) / rm]
P = principal, PMT = monthly contribution, r = annual rate, n = compounds/year, rm = r/12, m = months, t = years. Returns are user-assumed and not guaranteed.
Source: Standard compound interest / annuity future-value formula.
Frequently Asked Questions
Is daily compounding much better than monthly?
Better, but only slightly. At typical rates the difference between daily and monthly is well under 1% — the leap from annual to monthly is much larger than from monthly to daily.
Where is daily compounding used in practice?
Most online high-yield savings accounts, money-market funds, and credit-card balances accrue interest daily.
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Investment Disclaimer: Calculations are estimates based on assumptions. Past performance does not guarantee future results. Investments involve risk, including potential loss of principal. SmartStockCalcs is not a registered investment advisor. For educational purposes only — consult a licensed financial advisor before making investment decisions.
Last updated: June 6, 2026