Daily Late Fee & Interest Calculator (Simple & Compound)
Calculate cumulative late fees and interest penalties for overdue payments. Supports grace periods, weekend/holiday exclusions, and customizable interest compounding rules.
Days Overdue: 0
Chargeable Days: 0
About
Late payments disrupt cash flow and contract adherence. This calculator quantifies the financial impact of overdue invoices, rent, or loans based on specific contractual terms. It differentiates between simple daily fees and percentage-based interest models, providing a precise breakdown of the total debt obligation.
Accurate calculation is vital for legal compliance and dispute resolution. Many jurisdictions impose limits on usury or compound interest on penalties. This tool allows you to model "Grace Periods" (time before fees accrue) and toggle "Business Days Only" to exclude weekends and federal holidays from the fee schedule, ensuring your demand letters or payment reminders adhere strictly to the agreed-upon terms.
Formulas
For Simple Interest, the formula for total accumulation is:
For Compound Interest (compounded daily), the formula is:
Where:
- A = Total Amount (Principal + Interest)
- P = Principal Amount
- r = Annual Interest Rate (decimal)
- n = Compounding frequency (e.g., 365)
- t = Time in years (Days Late / 365)
Reference Data
| Parameter | Description | Standard Practice |
|---|---|---|
| Grace Period | Days allowed before fees start | 3 - 5 days (Rent), 30 days (Net30) |
| Simple Interest | Fee calculated on principal only | Common in personal loans |
| Compound Interest | Interest calculated on principal + accumulated interest | Common in credit cards & banks |
| Usury Limit | Legal maximum interest rate cap | 5% to 25% (varies by State) |
| Leap Year | Handling of Feb 29 | Denominator 366 vs 365 |
| Accrual Basis | Day count convention | Actual/360 (Commercial), Actual/365 (Consumer) |
| Fixed Fee | Flat penalty per occurrence | $25 - $50 |
| Daily Cap | Maximum daily accumulation | Often capped at 10% of Principal |