Late Payment Fee Calculator
Calculate late payment fees and penalties on overdue bills.
See how late fees, interest charges, and compounding add up over time.
Total Late Fees
Late payment fees can include a flat fee plus penalty interest on the overdue amount:
Total Flat Fees = Flat Fee × Number of Late Periods
Penalty Interest = Balance × (Penalty Rate / 100 / 12) × Months Late
If the penalty interest compounds monthly:
Compounded Balance = Balance × (1 + Penalty Rate / 100 / 12)^Months
Total Penalty Interest = Compounded Balance - Original Balance
Example: $1,000 bill, $35 flat late fee per month, 29.99% penalty APR, 3 months late:
- Flat fees = $105 (3 × $35)
- Penalty interest (compounded) = $76.87
- Total cost of being late = $181.87
Common late fee structures:
- Credit cards: $29-40 flat fee + penalty APR (up to 29.99%)
- Mortgages: 4-5% of monthly payment
- Rent: $25-100 flat or 5-10% of rent
- Utilities: 1-5% of bill or small flat fee
Tips:
- Set up autopay to avoid late fees entirely
- Call your provider — first-time late fees are often waived
- Credit card penalty APR can stay elevated for 6+ months
- Late payments over 30 days can damage your credit score