Here's a brief summary of how to estimate your bill: To get an estimate of your electricity bill with a particular plan, you will need a few numbers found on the plan's Electricity Facts Label (EFL): Base charge Energy rate per kilowatt-hour (kWh)a Transmission and Distribution Utility delivery charges You'll also need your historical energy usage. You can find this information on your past bills. Follow these steps to estimate your electricity bill: Multiply your energy rate by your energy usage. Multiply your usage-based (per kWh) TDU charge by your energy usage. Add your costs from Step 1 and Step 2, along with your base charge and fixed TDU charge. This should give you an estimation of your electric bill amount for that plan. Be sure to keep a few things in mind: Your bill amount can vary month to month based on your energy usage and any changes to the TDU delivery charges. Your energy usage can change due to weather, habits, appliance efficiency and many other factors. The most extreme changes in usage can occur when weather temperatures are highest or lowest, causing your AC or heater to use more electricity. With a fixed-rate plan, your energy rate per kWh stays the same for a designated number of months and with a variable-rate plan, your rate could change month over month.