kWh Cost Calculator

To find the cost of electricity, multiply the kilowatt-hours by your price per kWh. 30 kWh at $0.17/kWh costs $5.10. One kilowatt-hour at that rate is 17 cents. If you use 30 kWh every day, that projects to about $153 a month and $1,862 a year. The calculator above does the multiplication and the projections the instant you enter your own rate.

A kilowatt-hour is the fundamental unit of energy billing worldwide: it is the energy of a 1,000-watt load running for one hour. Your electricity meter counts kWh, and your utility charges a set price for each one. This tool exists to convert that count into money quickly and accurately — and because you enter the rate you actually pay, the answer is exact for your home rather than a generic estimate.

This is the most direct cost formula in electricity:

There is nothing to convert — kilowatt-hours are already the billing unit. If you know the energy and the rate, one multiplication gives the cost. Some quick reference points at $0.17/kWh:

• 1 kWh = $0.17
• 10 kWh = $1.70
• 30 kWh = $5.10
• 100 kWh = $17.00
• 1,000 kWh = $170.00

Where does the kWh figure come from? You might read it directly off a smart meter or an energy monitor, subtract two meter readings, or calculate it from a device's power and run-time. To get kWh from watts, use kWh = (Watts × Hours) ÷ 1000 — that is exactly what the energy usage calculator does. Once you have kWh, this tool turns it into dollars. For a device you know only in amps, convert with the AC amps to watts calculator first.

These examples cover the situations where people most often need to price kilowatt-hours.

Example 1 — Reading a smart meter. Your energy monitor shows the house used 30 kWh yesterday. At your rate of $0.17: 30 × 0.17 = $5.10 for the day. If yesterday was typical, the monthly projection of $153 gives you an early read on the coming bill.

Example 2 — Charging an electric vehicle. A full charge adds 60 kWh to your EV battery. At $0.14/kWh off-peak: 60 × 0.14 = $8.40 per full charge. Compared with $3.50/gallon gasoline, that is dramatically cheaper per mile — the kind of comparison this calculator makes easy.

Example 3 — A single appliance session. An electric oven used for a 2-hour roast consumes about 4 kWh. At $0.20/kWh: 4 × 0.20 = $0.80 for the meal. Small, concrete numbers like this help demystify where the bill comes from.

Example 4 — Monthly whole-home usage. Your bill says you used 850 kWh. At $0.19/kWh: 850 × 0.19 = $161.50 in energy charges (before any fixed fee). To add the fixed service charge, move to the electricity bill calculator.

The multiplication in this tool is trivial, but the rate you multiply by is where accuracy lives — and only you can supply it. Published "average" electricity prices are a moving target and vary by more than 4× across US states, so any answer built on an assumed rate is unreliable for a specific household.

Find your true rate in one step: divide your most recent bill's total by the kilowatt-hours it lists. That blended figure includes generation, delivery, transmission, and taxes — the real cost of your next kilowatt-hour. Enter it here and every conversion becomes exact.

This is precisely the sort of question where a generic answer fails and a personalized calculator succeeds. Asking "what does a kWh cost" in the abstract has no single right answer; asking it with your rate has an exact one. If you are on a time-of-use plan, you can enter your peak rate and your off-peak rate separately to see how much a given block of energy costs at each — useful for deciding when to run the dishwasher, do laundry, or charge an EV.

A kilowatt-hour (kWh) is a unit of energy, not power. It equals one kilowatt (1,000 watts) of power sustained for one hour. Equivalent statements: 1 kWh is 100 watts for 10 hours, or 2,000 watts for 30 minutes, or 40 watts for 25 hours. In all cases the power multiplied by the time equals 1,000 watt-hours = 1 kWh.

This distinction trips people up constantly. Watts measure the rate of energy use at an instant — how hard a device is drawing right now. Kilowatt-hours measure the total energy used over time — the accumulation that your meter records and your utility bills. A 100 W bulb and a 100 W laptop draw the same power, but if the bulb runs 10 hours and the laptop 2, the bulb used 5× the energy and costs 5× as much.

Because the bill is in kWh, converting any usage into kWh is the key step before pricing it. The chain is: amps → watts → watt-hours → kilowatt-hours → dollars. This calculator handles the final link. For the earlier links, the energy usage calculator converts watts and hours into kWh, and the power consumption calculator sums many devices. Understanding kWh deeply also helps you read solar production, battery capacity, and EV range, all of which are quoted in kWh.

1. Enter the energy in kilowatt-hours. Read it from a meter or monitor, subtract two meter readings, or compute it with the energy usage calculator if you only know watts and hours.
2. Enter your electricity rate. Use your blended rate (total bill ÷ kWh) for the truest figure, or a specific peak/off-peak rate to compare.
3. Read the cost. The primary result is the dollar cost of that energy. The monthly and yearly figures assume the same amount is used every day — handy for turning a daily meter reading into a bill forecast.

If the energy you entered is a one-time amount rather than a daily figure, ignore the monthly and yearly projections and use only the primary cost.

Pricing kilowatt-hours comes up more often than you might expect once you have the number handy.

Checking a meter or monitor. Smart meters, whole-home monitors, and plug-in watt-meters all report kWh. Converting that to money tells you instantly whether a day, an appliance, or a habit is expensive.

EV charging costs. Electric vehicles are rated in kWh per charge and kWh per 100 miles. Multiply by your rate to get cost per charge or cost per mile, then compare against gasoline. Off-peak charging often halves the cost — worth modeling with both rates.

Solar and battery planning. Solar production and battery storage are quoted in kWh. Pricing a day's solar generation at your rate shows the daily value of a system; pricing a battery's usable capacity shows what one full discharge is worth during an outage or peak period.

Splitting shared bills. If you sub-meter a workshop, rental, or EV charger, this tool converts the sub-meter's kWh into a fair dollar amount to bill back. For a full statement with fixed charges, continue to the electricity bill calculator; to break usage down by appliance, use the appliance running cost calculator.

Since this calculator prices kilowatt-hours, the first step is getting an accurate kWh figure. There are several dependable sources, each suited to a different question.

Subtract two meter readings. Your electric meter — analog dial or digital — counts total kWh. Record the reading, wait a day or a week, and subtract. The difference is the energy used in that window. This captures everything in the home, which is ideal for whole-house pricing.

Read a smart meter or utility app. Many utilities now show daily and even hourly kWh online. Copy the figure straight in. Hourly data is especially useful on time-of-use plans, letting you price peak and off-peak energy separately.

Use a plug-in energy monitor. A watt-meter between the outlet and a single device accumulates that device's kWh over time — the cleanest way to isolate one appliance's real consumption, cycling and all.

Calculate from watts and hours. When you cannot measure, compute: kWh = (watts × hours) ÷ 1000. The energy usage calculator does this and hands you a kWh figure to price here. However you obtain the number, this tool turns it into money at your exact rate.

One kilowatt-hour is a surprisingly large amount of energy, and picturing what it does helps sanity-check any cost estimate. For the price of a single kWh — around 17 cents on average — you can accomplish a lot: run a 10-watt LED bulb for 100 hours, brew roughly 40 cups of coffee, wash and partially dry a load of laundry, power a laptop for a full workweek, or keep a modern refrigerator cold for the better part of a day.

That perspective explains why some habits barely move a bill while others dominate it. Leaving a phone charger plugged in wastes a fraction of a kWh a month; running an electric clothes dryer just once uses 3–4 kWh, more than that charger will draw in years. When a cost figure from this calculator surprises you, translating it back into kilowatt-hours and comparing against these anchors usually reveals whether the number is reasonable. It also makes the value of efficiency concrete: every kWh you avoid is 17 cents kept, and across thousands of kilowatt-hours a year those cents become the difference between a high bill and a low one. For the physics behind the unit, see kWh explained.

• Confusing kW with kWh. A 5 kW load is not 5 kWh — you must multiply by the hours it runs. Only kWh (energy) can be priced.
• Using watt-hours instead of kilowatt-hours. Divide watt-hours by 1,000 first. 5,000 Wh is 5 kWh, costing $0.85 at $0.17 — not $850.
• Applying the wrong rate. Peak vs off-peak, or base vs blended, can differ by 2×. Enter the rate that matches the energy you are pricing.
• Misreading the monthly projection. The monthly and yearly outputs assume the entered energy repeats every day; do not apply them to a one-off amount.
• Forgetting the fixed charge. This tool prices energy only; a full bill adds the fixed service fee.

Keep units straight and use the right rate, and pricing kilowatt-hours becomes foolproof.