How do I calculate a utility bill late fee?
Start with the unpaid balance, then add the flat late fee, percentage late fee, and any daily interest shown by the utility. Some utilities have grace periods, caps, or waiver rules.
Utility bill late fee calculator
Estimate how late fees change the amount due.
Use this when a utility bill, past-due notice, or portal lists a flat late fee, percentage penalty, daily interest, or partial payment.
Electric bill
$226
Energy$142
Delivery$48.00
Fees$36.00
All-in rate
$0.246 per kWh
Best next check
Cooling hours
Late fee inputs
Enter the fee rules printed on the bill, notice, or utility portal.
Total due estimate
$198
$185 unpaid balance plus $12.78 late fees.
Late fees
$12.78
6.9% effective penalty on the unpaid balance.
Unpaid balance
$185
Bill amount minus any partial payment entered.
Fee share
6%
Late fees as a share of the estimated total due.
Late fee breakdown
Original bill amount
The amount due before any late fee is added
$185
Partial payment
Payment already made before calculating the unpaid balance
-$0.00
Flat late fee
One-time fee entered from the bill
$10.00
Percentage late fee
1.5% of unpaid balance
$2.78
Daily interest
0% per day for 12 day(s)
$0.00
Before paying a late amount
Use the fee labels from your bill or utility notice. Some utilities waive or cap late fees under local rules.
This is an estimate from the fee inputs you enter. Confirm the final amount, grace period, shutoff notice rules, and payment-plan options with the utility.
Use the late-fee result next
Billing days calculator
Check whether the bill covered a longer period before treating the late fee as the main problem.
Open pageUtility bill payment plan calculator
Spread a past-due balance over several months while keeping the current bill in the estimate.
Open pageUtility bill audit checklist
Review due dates, balances, estimated reads, fixed charges, and unusual line items.
Open pageFAQ
Short answers for search visitors and bill-checking moments.
Does a partial payment reduce late fees?
It can, depending on the utility rule. This calculator applies percentage and daily fees to the unpaid balance after the partial payment you enter.
Is this the final amount I owe?
No. Treat it as an estimate from the fee rules you entered. Confirm the final balance, grace period, payment plan, and disconnection rules with the utility.