Electricity Cost Calculator
Calculate monthly and annual electricity cost for any device or appliance from wattage and usage hours.
Results
What is it?
The Electricity Cost Calculator computes the monthly and annual cost to run any electrical device based on its power rating (watts), daily usage, days used per month, and your local electricity rate ($/kWh). It helps you identify energy hogs and prioritize efficiency upgrades.
How to use
Find the wattage on the device label or in its manual. Enter how many hours per day you typically use it and how many days per month. Enter your electricity rate from your utility bill (or use the US average of $0.13–$0.16/kWh). The calculator shows daily kWh, monthly kWh, and monthly and annual costs.
Example scenario
A 1500 W space heater used 6 hours/day for 30 days at $0.15/kWh costs: 1500/1000 × 6 × 30 × $0.15 = $40.50/month or $486/year. Compared to turning it down or using it 4 hours instead of 6 (saving $13.50/month), the payoff of a programmable thermostat is immediate.
Pro tip
Standby or "vampire" power is real — TVs, gaming consoles, and phone chargers consume 0.5–5 W even when off. A household can have 20–40 such devices, adding $50–100/year. Use a smart power strip or unplug devices when not in use. The biggest energy users in a typical home are: HVAC system (46%), water heater (14%), washer/dryer (13%), refrigerator (4%), and lighting (4%).