Published October 23, 2026 · By RegionalRates
Start with the bill, not a shopping list. A higher total can come from more electricity, a higher price, a longer billing period, or charges unrelated to this month's use. Compare those separately before blaming an appliance.
1. Separate the amount due from this month's charges
Check for a previous balance, late fee, deposit, credit adjustment, or installment payment. If your amount due includes a $60 balance from last month, that $60 is not evidence that your home used more electricity this month.
Budget or level-payment plans can also make the payment differ from the cost of that period's consumption. Find the usage and current-charge sections, and ask the utility how any payment-plan adjustment was calculated.
2. Compare kWh per day
Two bills may cover different numbers of days. Divide each period's kWh by its billing days before deciding whether your usage increased.
| Period | Usage | Days | Daily average |
|---|---|---|---|
| Earlier bill | 900 kWh | 30 | 30 kWh |
| New bill | 1,050 kWh | 35 | 30 kWh |
Total consumption rose by 150 kWh, but daily consumption stayed the same. This does not explain every charge; it simply prevents a longer month from looking like a change in habits. A daily average is also not weather-normalized: a hotter or colder period can still explain higher daily use.
3. Check the usage-based rate and fixed fees
At the same illustrative 900 kWh, a variable rate increase from 16 to 18 cents per kWh adds $18. That is 900 × $0.02. A fixed customer charge increasing from $12 to $15 adds another $3, regardless of use. These examples exclude taxes and other changes.
Compare the actual bill components instead of dividing the total amount due by kWh and treating the result as your energy-only rate. Our guide to finding your electricity rate explains the difference. The comparison calculator can model two simple rate-and-fee structures.
4. If daily use increased, look for a change in routine
Compare the bill dates with changes in weather, occupancy, equipment, and schedules. Did you add an electric vehicle, run a dehumidifier, use a portable heater, extend a pool-pump schedule, or have more people using hot water? These are questions to investigate, not a diagnosis of your home.
Make a short list with an estimated power draw and operating time for each change. An additional average 500 watts for four hours a day uses 60 kWh over 30 days, costing $9.60 at an illustrative 16 cents. It would not, by itself, explain an extra $100.
5. Use the information you already have
If your utility account provides daily or interval data, find when the increase began and whether it appears throughout the day or at particular times. Availability and detail vary by utility. Match the billing dates and account meter when comparing downloads.
Check whether the bill identifies an actual or estimated meter reading. If a reading or adjustment is unclear, contact the utility. Do not open, alter, or bypass a meter. A household monitor is useful for investigating patterns, but does not independently establish that a utility meter is faulty.
Choose the next step from the evidence
- Daily use is stable, price is higher: check tariff changes, adjustments, and fees with your utility.
- Use rises during cooling hours: review your AC operating-cost estimate and have faults assessed by a qualified technician.
- A pump schedule changed: compare watts and hours in the pool-pump guide.
- One plug-in appliance is still a question: read how to choose an electricity monitor before buying one.
For payment difficulty, contact the utility about current assistance or payment arrangements. For an unexplained bill, bring the two bills and your daily-use comparison to customer service.
Sources and calculation notes
Utility reference: Duke Energy: Avoid Surprise Bills, including billing-period differences. General household energy reference: DOE Energy Saver Guide, 2022. Numerical examples are RegionalRates scenarios, not typical bills or current tariffs. Read our methodology.