Work out average daily balance interest instantly with clear inputs, formula shown and shareable results.
Interest and fee waivers are assessed on the average daily balance, not the opening or closing figure. Weighting each balance by the days it was held shows why a brief high balance does little for the average.
Average daily balance
ADB = Σ(balance × days) / days in month; interest = ADB × rate × days / 365
Figures are estimates based on the inputs given. Bank charges, regulatory minima and market rates change and differ between institutions and jurisdictions. This is not financial advice — confirm with your bank or treasury policy.
It reflects the funds actually available to the bank across the period rather than a single snapshot.
Considerably. Money in for the whole month counts fully; money in for three days barely registers.