Free appliance & EV running-cost calculator

See what every appliance is really costing you — per hour, day, month and year.

Pick an appliance or your EV charger, we fill in the watts, you set your rate — and see the real dollar cost. No signup, no email, nothing sent anywhere. It all runs in your browser.

No signup No tracking 100% free Runs in your browser
RUNNING COST $ / hr · day · mo · yr hrdaymoyr Save ~$120/yr run it 1h less a day
Built on real data
EIA electricity rates DOE / ENERGY STAR wattages Manufacturer power specs Nothing sent anywhere
Your instant estimate — runs entirely in your browser
watts
5 h
$/kWh

Plug-in heaters run at 1,500W on high — there is no low-power mode that still heats a room.

Running a space heater at 1,500W for 5 h a day costs about

$38.81/ month  ·  $465 / year
$0.26
per hour
$1.28
per day
$38.81
per month
$465
per year
That's about 25% of a typical home's monthly electricity use.
Each day it uses 7.50 kWh — enough to drive an electric car about 26 miles.
Running it just one hour less a day would save about $93.08 a year. Heat the one room you're in and shut the door, instead of fighting a cold house.
Shopping for a more efficient one?
A newer, higher-efficiency space heater can cut what it costs to run — here's where to compare.

Independent suggestion — we don't sell your information or send anything anywhere.

How it works

From "what's that thing costing me?" to an answer in seconds

No nameplate hunting, no spreadsheet — we fill in the hard numbers and show every step of the math.

1

Pick your appliance

Choose from 50+ presets — space heater, dryer, pool pump, fridge, gaming PC, Level 2 EV charger and more. We fill in a typical wattage so you never need the nameplate.

2

Set your rate

Use your region's average rate or type the exact $/kWh from your bill, then slide the hours-per-day to match how you actually use it.

3

See the real cost

Get the cost per hour, day, month and year instantly — plus how much running it one hour less would save. Switch to whole-home mode to rank everything biggest-first.

Why WattDollar

The honest number, not a sales funnel

No account wall, no data harvesting — just a transparent calculator whose math you can see and check.

No signup, no email

No account, no lead form, no newsletter wall. It works the instant the page loads — and every number stays on your device.

Built on real data

Rates from EIA regional averages; wattages from DOE / ENERGY STAR and manufacturer specs. No made-up figures, no fake reviews.

Transparent math

The whole formula — (watts ÷ 1,000) × hours × your price per kWh — is shown right on the page. Change any input and watch the cost move.

Built to save you money

Every result shows what running it one hour less would save, and whole-home mode points straight at your single biggest drain.

For retailers, EV-charger brands & energy programs

Put an honest running-cost calculator in front of ready-to-buy shoppers

WattDollar reaches people at the exact moment they're deciding whether an appliance, heat pump or EV charger is worth it — and what a more efficient model would save. A warm, high-intent audience, with no lead form in the way.

  • Embeddable & co-brandable — drop the calculator on your product or store page so shoppers see real running costs without leaving.
  • Warm, high-intent traffic — visitors arrive already shopping by appliance type; the results screen is the natural place to recommend an efficient model.
  • Affiliate & revenue-share friendly — one editable config points the "shop a more efficient model" link at your store, Amazon tag or charger lineup.

How this works

Every electrical appliance has a power rating in watts. The cost to run it is simple: (watts ÷ 1,000) × hours used × your price per kWh. The hard parts are knowing the wattage and knowing your rate — so WattDollar does both for you. Choose an appliance and we fill in a typical wattage; pick your state or country and we fill in the average electricity price. Change either to match your exact situation.

The single-appliance view answers the literal question — "what does my space heater cost?" — but the real question is usually "where is my bill going?" That's what whole-home mode is for: list everything you run and WattDollar ranks them biggest-first, so you can see at a glance that the pool pump or the old garage fridge is costing more than everything you were worried about. Everything runs on your device; nothing you enter is sent anywhere.

Common questions

How do you work out the cost?

Cost = (watts ÷ 1,000) × hours run × your price per kWh. A 1,500W heater for 5 hours at $0.17/kWh is 1.5 × 5 × 0.17 = about $1.28 a day. WattDollar fills in the watts and a typical local rate so you don't have to look anything up.

Where do I find my electricity rate?

It's the price per kilowatt-hour (kWh) on your bill — usually something like $0.17. We pre-fill the average for your state or country, but your exact rate gives the most accurate answer. Pop it into the "price per kWh" box.

I don't know my appliance's wattage — is that a problem?

No. Pick the closest match from the list and we use a typical wattage for it. If you want to be precise, the real figure is usually printed on a label on the appliance or in its manual, and you can type it in.

Why doesn't the fridge run 24 hours?

Appliances like fridges and freezers cycle — the compressor only runs about a third of the time to hold temperature. So the default "hours per day" reflects actual run time, not the hours it's plugged in. The result lands around the real 1–2 kWh a day a fridge uses.