Rate-plan tool

Time-of-Use Electricity Cost Calculator

Separate peak and off-peak kWh, calculate a blended price, and test the value of shifting flexible loads.

Free and private Editable assumptions Formula shown

Your inputs

Build your scenario

kWh/mo
$/kWh
kWh/mo
$/kWh
$/mo
kWh/mo

Live estimate

Modeled time-of-use bill$197.501000 kWh at a $0.198 blended price
Peak charges$101.50
Off-peak charges$78.00
Shift 100 kWh$17.00 saved
Transparent calculation350 peak kWh × $0.290 + 650 off-peak kWh × $0.120 + $18.00

Verify the rate schedule, seasonal periods, delivery prices, minimum bills, and any demand charge before changing plans.

How this calculator works

Estimate a time-of-use electricity bill from peak and off-peak consumption, rates, fixed charges, and a load-shifting scenario.

peak kWh × peak rate + off-peak kWh × off-peak rate + fixed charges

Time and energy both matter

A time-of-use plan assigns different prices to defined windows. The same monthly kWh can produce a different bill depending on when EV charging, water heating, laundry, cooling, and other flexible loads operate.

Model only loads that can actually move

The calculator tests a shift from peak to off-peak hours without changing total kWh. Do not assume essential heating, cooling, cooking, or medical loads can always move.

  • Check weekday, weekend, holiday, and seasonal schedules.
  • Include delivery rates if they also vary by time.
  • Confirm whether demand charges apply separately.

Compare the full rate plan

A lower off-peak rate does not automatically make a plan cheaper. Peak prices, fixed charges, minimum bills, demand charges, export credits, and seasonal definitions can outweigh savings from shifted energy.

Frequently asked questions

What is a blended electricity price?

It is total modeled charges divided by total kWh. It summarizes the result but does not replace the underlying peak and off-peak rates.

Does shifting load reduce energy use?

Not necessarily. This scenario keeps total kWh constant and changes only when the electricity is consumed.

Are demand charges included?

No. Residential demand charges require a separate maximum-kW calculation unless explicitly added to the fixed-charge input.

Primary references

Use equipment documentation, your utility rate schedule, and measured data when they are available.