Electricity Cost from Energy Consumption
Electricity Cost from Energy Consumption
Every electricity bill boils down to this one multiplication: energy consumed (in kilowatt-hours) times the price charged per kilowatt-hour. Understanding this relationship is what lets someone translate "I ran my AC for 8 hours" or "my EV charged overnight" into an actual dollar figure, rather than just waiting for the bill to arrive.This same per-kWh cost is the number behind every energy-saving recommendation — switching to LED bulbs, upgrading an old appliance, or adjusting a thermostat setpoint — since the savings from reduced kWh consumption only becomes a concrete dollar figure once multiplied by the local electricity rate.
The electricity cost is simply cost = E × rate, energy consumed multiplied by the price per kilowatt-hour. where E_used is the energy consumed in kilowatt-hours and rate_kwh is the price per kilowatt-hour, giving the resulting cost_elec in dollars (plain number, no currency unit).
Inputs
E_used := 350 kWh=1.26e+09 Nm
rate_kwh := 0.15=0.15
Strip the kWh unit down to a plain number by dividing by one kilowatt-hour, since the rate itself is a plain dollars-per-kWh number with no currency unit in this engine.
E_num := E_used/(1 kWh)=350
Multiply the plain-number energy consumption by the plain-number rate to get the total dollar cost.
cost_elec := E_num·rate_kwh=52.5
Results
Consuming 350 kWh at 15 cents per kWh comes out to $52.50 for the billing period — a figure that lines up with a typical monthly residential electricity bill. Because cost scales linearly with consumption, cutting usage by a given percentage (say, running the AC less) saves that same percentage on the bill directly, which is the simplest lever available before considering a rate plan change.
Assumptions & limitations
- Flat rate per kWh (no tiered pricing or time-of-use rate structure).
- No fixed monthly service charges or taxes included.
- Metered consumption is accurate for the full billing period.