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A practical time-of-use energy cost scenario
For this example, use peak-period use of 220 kWh, peak price per kwh of 0.34, off-peak use of 430 kWh, off-peak price per kwh of 0.14, and fixed monthly charge of 18. These are starting values, so replace them with numbers that match your situation.
Peak-period use: 25% lower
Change peak-period use to 165 kWh while keeping the other example values the same.
Peak-period use: 25% higher
Change peak-period use to 275 kWh while keeping the other example values the same.
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Quick answer
What does the Time-of-use energy cost calculate?
What does electricity cost across peak and off-peak periods? This calculator uses peak-period use, peak price per kwh, off-peak use, off-peak price per kwh, and fixed monthly charge to estimate blended electricity cost immediately in your browser.
With the values currently entered, the result is $153.00 — monthly time-of-use cost. It also shows peak cost, off-peak cost, and blended usage rate.
How to use the Time-of-use energy cost
- Replace the example values with your own numbers.
- Review the result and supporting figures as they update automatically.
- Check the formula and assumptions before using the estimate for a decision.
Inputs used
- Peak-period use — entered in kWh
- Peak price per kWh
- Off-peak use — entered in kWh
- Off-peak price per kWh
- Fixed monthly charge
Time-of-use energy cost formula
Peak use × peak rate + off-peak use × off-peak rate + fixed charge
Assumptions
- All usage fits one of the two periods.
- Demand charges and taxes are excluded.
Verify the inputs
Authoritative sources
These sources explain the definitions, factors, or rules behind this tool. Their geographic scope is shown because an official source for one country is not automatically valid somewhere else.
Sources do not endorse Calculum. Check the source date, scope, and your own documents before making a financial, tax, insurance, or reporting decision.
Practical guide
Time-of-use energy cost example and edge cases
What does electricity cost across peak and off-peak periods? Let's use a concrete example, then look at the assumptions that can move the answer.
Example: A practical time-of-use energy cost scenario
For this example, use peak-period use of 220 kWh, peak price per kwh of 0.34, off-peak use of 430 kWh, off-peak price per kwh of 0.14, and fixed monthly charge of 18. These are starting values, so replace them with numbers that match your situation.
- Peak-period use
- 220 kWh
- Peak price per kWh
- 0.34
- Off-peak use
- 430 kWh
- Off-peak price per kWh
- 0.14
- Fixed monthly charge
- 18
Calculated result$153.00monthly time-of-use cost
Start with monthly time-of-use cost. Then check peak cost, off-peak cost, and blended usage rate to understand what sits behind the main result.
Example results use the default display profile. The calculator above follows your selected country and units.
How to read the result
- Read the main result first. The supporting figures for peak cost, off-peak cost, and blended usage rate explain how the estimate is built.
- The method is Peak use × peak rate + off-peak use × off-peak rate + fixed charge. Keep the units consistent and use values from the same time period.
Edge cases worth checking
When peak-period use is unusual
All usage fits one of the two periods. Double-check this input before relying on the result.
When fixed monthly charge is uncertain
Demand charges and taxes are excluded. Run a lower and higher value to see a useful range.
What changes the result most
Peak-period use
Keep peak-period use on the same time basis as the other inputs. Monthly and annual values are easy to mix up.
Peak price per kWh
Use a current amount for peak price per kwh. Include fees or recurring costs that belong in the same figure.
Off-peak use
Measure off-peak use with the same unit shown beside the input. Convert first if your source uses another unit.
Try a different scenario
Small changes show whether the answer is stable or sensitive.
Peak-period use: 25% lower
165 kWh$134.30monthly time-of-use cost
Peak-period use: 25% higher
275 kWh$171.70monthly time-of-use cost
Peak price per kWh: 25% higher
0.425$171.70monthly time-of-use cost
Common mistakes
Check peak-period use
All usage fits one of the two periods. Make sure this matches the number you enter.
Keep fixed monthly charge consistent
Demand charges and taxes are excluded. Use the same units and time period throughout the calculation.
Do not rely on one time-of-use energy cost scenario
Run a cautious case and an optimistic case. The range is often more useful than one exact-looking number.
Use this result well
What does electricity cost across peak and off-peak periods?
Actual tariffs, weather, equipment behavior, and fixed charges can change the bill.