Comprehensive Guide
Learn more in our Loans & Mortgage Guide.
How it works
An overdraft is functionally a micro-loan: the bank covers a transaction your balance cannot, then bills a flat fee for the privilege. Framing the fee as a rate exposes the economics. A $35 fee covering a $60 shortfall for three days is $35 of interest on $60 for 3 days — an annualized rate near 7,000%, far beyond any payday lender's legal maximum in most states. The calculator performs that conversion for your own numbers, showing the effective APR, the fee's share of the shortfall, and how the implied rate collapses as either the gap grows or the days stretch — a $35 fee covering a $500 hole for ten days is merely 255% APR. Two companion insights follow from the table. Small shortfalls produce absurd rates, which is why regulators have focused on fee-to-coverage ratios; and extended-overdraft fees around day five stack additional charges onto an already extreme base. The comparison this tool exists to make: nearly any alternative — a card purchase, a credit-union PAL, even a payday loan in capped states — supplies the same liquidity at a fraction of the annualized price. The habit fix lives elsewhere; this page prices the event.Formula
Effective APR = fee ÷ shortfall × 365 ÷ days negative × 100
Tips
- Declining debit overdraft coverage makes declines free — opt out unless coverage truly helps.
- The smaller the shortfall, the wilder the rate: protect large-ticket timing, not $20 gaps.
- Extended fees around day five compound the damage — clear negatives within days, not weeks.
- One cash advance or PAL at 28–36% beats almost any single overdraft event.
- Count annual events separately — two a month is a habit problem worth its own audit.