Electricity Rate Comparison Calculator
Compare flat-rate electricity pricing against Time-of-Use (TOU) on-peak and off-peak tariffs, calculating your break-even on-peak threshold.
Flat Rate vs Time-of-Use (TOU)
Time-of-Use vs Flat-Rate Equation
TOU Cost = (On-Peak kWh × Peak Rate) + (Off-Peak kWh × Off-Peak Rate) | Break-Even Peak % = (Flat Rate - Off-Peak Rate) ÷ (Peak Rate - Off-Peak Rate)- Flat Rate: Uniform price per kilowatt-hour regardless of the time of day.
- TOU On-Peak: Expensive power hours when regional grid demand peaks (typically weekdays 4 PM to 9 PM).
- TOU Off-Peak: Discounted overnight, morning, and weekend electricity rates.
- Break-Even Peak %: Maximum percentage of energy you can use during on-peak hours before TOU costs more than flat-rate.
Step-by-Step Worked Example
Calculation Steps:
How to Use This Calculator
Assumptions & Limitations
- Assumes two-tier TOU structure (On-Peak vs Off-Peak).
- Break-even formula assumes identical total monthly kWh consumption.
Frequently Asked Questions
Is Time-of-Use (TOU) electricity pricing worth it?
TOU is highly beneficial if you can shift heavy electricity use (charging an electric vehicle, running dishwashers or laundry, running pool pumps) to overnight or morning off-peak hours. However, if your home requires heavy air conditioning during 4 PM to 9 PM, flat rates may be cheaper.
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