Time-of-Use Electricity Savings Calculator
Should you switch to time-of-use electricity? Compare your current plan with rates that change by time of day, then explore moving flexible usage to cheaper hours.
Start with the rates and usage timing from your own utility. The numbers below are examples, not a utility quote or a forecast.
Your Estimated Electricity Costs
Estimated TOU Savings
/ month/ year ·
Current Flat-Rate Plan
- Monthly Energy Cost
- Monthly Fixed Charge
- Estimated Monthly Total
- Estimated Annual Total
Time-of-Use Plan
- Monthly Energy Cost
- Monthly Fixed Charge
- Estimated Monthly Total
- Estimated Annual Total
| Period | Usage % | Estimated kWh | Rate ($/kWh) | Estimated Monthly Cost |
|---|
Selected Schedule Changes
Your rate-plan comparison uses the usage percentages entered above. The load-shifting planner separately shows what selected schedule changes could save.
Add loads above to estimate schedule-change savings.
| Load | Energy / Use | Current Period | New Period | Result | Per Use | Per Month | Per Year |
|---|
Total Estimated Load-Shifting Savings
/ month/ year
Monthly load savings are an average: 52 weeks of the entered schedule divided by 12. They are not added to the plan comparison.
The selected loads exceed your entered household annual electricity use. Check power and schedules. These separate planner estimates do not adjust your TOU allocation.
How it works
A flat-rate plan charges the same entered energy rate for all usage. Time-of-use (TOU) plans charge different rates depending on when electricity is used. Peak periods generally have higher rates; off-peak periods generally have lower rates. Your utility's actual schedule determines which hours qualify.
For each TOU period, we multiply monthly electricity use by its usage share and rate. We add the entered fixed charge to each plan and repeat the modeled month 12 times for an annual estimate. A higher TOU total is shown as additional cost, not negative savings.
The load planner multiplies watts ÷ 1,000 by hours per use to find energy per use. Savings per use equal that energy times the difference between current and destination rates. Uses per week and 52 weeks give the annual result. Moving to the same period saves nothing; moving to a higher rate adds cost.
Understanding the estimate
TOU is not automatically cheaper. Whether switching saves money depends on your rates and when you use electricity. Shares must cover all monthly use, including inflexible loads. Use measured or manufacturer-supported power and realistic schedules; rated maximum watts may overestimate a cycling appliance.
This calculator compares entered energy rates and fixed charges only. Real bills may also include taxes, delivery charges, tiered pricing, demand charges, seasonal rates, minimum charges, credits and other utility-specific adjustments. Include applicable per-kWh charges in your entered rates where appropriate and confirm plan terms with your utility. We do not maintain a utility-rate database.
The annual estimate repeats one month; it does not forecast seasonal changes. Load-shifting assumes the whole use occurs in each chosen period. If a run crosses rate boundaries, split it into separate rows. Fractional uses per week are allowed for an average schedule. Percentage change is unavailable when current cost is zero.
Results are rounded for readability. Small differences below half a cent annually are described as approximately the same. CSV exports the displayed scenario, with separate plan and load totals. Custom names are protected against spreadsheet formula interpretation.