Investing & Wealth

Daily Compound Interest Calculator

Calculate investment and savings growth with daily interest compounding (365 times/year) and recurring monthly deposits.

What this calculator does

The Daily Compound Interest Calculator estimates your result instantly from the values you enter, using standard investing & wealth formulas. Calculate investment and savings growth with daily interest compounding (365 times/year) and recurring monthly deposits. Calculations run in your browser, so nothing you type is sent to a server, and the output is an estimate for planning rather than financial advice.

About Daily Compound Interest Calculator

The Daily Compound Interest Calculator models high-yield savings accounts, money market funds, and dividend reinvestment plans where interest compounds daily (n = 365).

Formula & Mathematical Calculation

A = P × ( 1 + r / 365 )^(365 × t) + PMT × [ (( 1 + r / 365 )^(365 × t) - 1) / (r / 365) ]

Calculation Example

$25,000 @ 5.0% APY Compounded Daily for 5 Years (+$200/mo deposit): Total Future Value = $45,862.14 (Interest Earned = $8,862.14).

Key Benefits

  • Models daily compounding interest (n = 365)
  • Supports initial principal plus recurring monthly or weekly deposits
  • Itemizes total principal contributed vs. total daily interest earned
  • Matches high-yield savings account bank calculations
  • Fast and private calculation

How to Use this Calculator

  1. Enter Initial Balance
    Input starting cash deposit.
  2. Enter Annual Interest Rate (%)
    Input annual interest rate.
  3. Add Regular Monthly Deposit
    Input additional monthly savings.
  4. Calculate Daily Growth
    Click Calculate to view daily compounding balance.

Assumptions & Limitations

What the calculation assumes

  • Every value you enter is treated as an exact, known amount.
  • Rates and contributions are assumed to stay constant for the whole period unless the form asks for them separately.
  • Results use standard financial formulas and ignore fees, penalties and promotional terms that are not entered above.
  • Inflation, tax changes and market volatility are not modelled unless a field for them is provided.
  • Amounts are unit-agnostic: results are returned in the same currency you enter.

What it does not cover

  • Daily Compound Interest Calculator produces estimates for education and planning, not a quote, offer or professional advice.
  • Real-world outcomes differ when fees, taxes, rounding rules or provider-specific terms apply.
  • Local regulations and tax rules vary by country and change over time; verify current rules for your jurisdiction.
  • Figures are only as accurate as the inputs you supply — check them before acting on the result.
  • For decisions with lasting financial impact, confirm the numbers with a qualified professional.

Frequently Asked Questions

On $100,000 at 5% over 10 years, daily compounding earns $64,872 in interest compared to $62,889 with annual compounding (an extra $1,983).