Every kWh on your meter has a dollar value once you know your rate. This guide shows how to calculate electricity cost from kWh—usage from bills or appliance math, your utility $/kWh, and the energy charge before fixed fees and taxes.
Benefits
- Core formula: cost $ = kWh × $/kWh.
- Works for one appliance, one day, or a full billing period.
- Reverse check: kWh = energy cost $ ÷ $/kWh when validating a bill line.
How it works
- Total your kWh—meter reading, bill summary, or watts × hours ÷ 1,000.
- Multiply by your energy rate in $/kWh from the tariff or effective bill rate.
- Read energy cost in dollars—add fixed charges separately for the full statement.
FAQ
How do I calculate electricity cost from kWh?
Cost $ = kWh × $/kWh. Example: 320 kWh at $0.16/kWh → 320 × 0.16 = $51.20 energy charge. For a single load: 1.5 kWh (1,500 Wh) at $0.14/kWh → 1.5 × 0.14 = $0.21 per cycle.
How do I get kWh from appliance wattage?
kWh = watts × hours ÷ 1,000. A 1,500 W heater for 4 hours → 1,500 × 4 ÷ 1,000 = 6 kWh. Multiply by your $/kWh for that run's cost, or use Appliance Monthly Energy for recurring loads.
Can I calculate cost without my full bill?
Yes—if you know kWh and rate, energy cost is pure multiplication. You still need your utility's fixed customer charge, delivery rider, and taxes for the total amount due. This math isolates the variable energy portion you control with usage.
Technical specifications
- Energy cost $ = kWh × rate_$/kWh.
- kWh from watts = W × hrs ÷ 1,000.
- Effective $/kWh = energy_charge $ ÷ billed_kWh.
- Related: electricity-bill-estimator, appliance-monthly-energy, energy-consumption.
kWh is the bridge between physics and dollars
Your utility does not bill watts directly—it bills energy over time. One kWh is 1,000 watt-hours: a 100 W bulb for 10 hours, or a 2,000 W dryer for half an hour. Once usage is in kWh, cost is one multiplication. That is how you price a single laundry load, a weekend of EV charging, or an entire month from the meter.
Build cost from the bottom up
Start with device kWh: space heater 6 kWh/night × $0.18/kWh = $1.08/night. Stack five loads and you have $5.40 before HVAC and baseline loads. Sum category kWh from Appliance Monthly Energy, then multiply the total by your rate for a usage-driven bill estimate—more accurate than guessing a dollar amount when you already know where the kWh go.
Reverse the formula to audit your bill
If energy charges were $142.80 and usage was 840 kWh, implied rate = 142.80 ÷ 840 = $0.17/kWh effective. Compare that to your published tariff—tier jumps and blended TOU periods often raise the effective rate above the off-peak sticker. Calculating cost from kWh forward and dividing backward catches billing surprises before they repeat next month.