Appliance Electricity Cost Calculator: kWh and CO2 per Year
Estimate the yearly kWh and electricity cost of each home appliance, standby included: water heater, heater, fridge, washer, TV, PC, plus the CO₂ footprint.
Whole-home electricity audit: kWh, cost and CO₂ per appliance
For each appliance, kWh/year = power (W) × hours per day × days per year ÷ 1,000, then cost = kWh × price per kWh. With the default list (water heater, fridge-freezer, washing machine, TV, router, heater), the home uses about 6,098 kWh a year: €1,220 at the French regulated rate of August 2026 (€0.2001/kWh on the Base option), the price the tool uses by default.
Method
The tool adds up a list of appliances, each with its power, hours of use per day and days of use per year (13 presets plus your own items). It derives kWh, annual, monthly and daily cost, and emissions: kWh × carbon intensity (55 g CO₂/kWh by default for France).
Example with the default list
| Appliance | Use | kWh/year |
|---|---|---|
| 200 L water heater, 2,200 W | 4 h × 365 d | 3,212 |
| Heater 1,500 W | 6 h × 140 d | 1,260 |
| Fridge-freezer 120 W | 24 h × 365 d | 1,051 |
| Washing machine 1,200 W | 1 h × 200 d | 240 |
| OLED TV 140 W | 4.5 h × 365 d | 230 |
| Router 12 W | 24 h × 365 d | 105 |
Total: 6,098 kWh, or €1,220 a year (€101.70 a month) at €0.2001/kWh and 335 kg of CO₂. The water heater alone costs €643, or €510 if it runs on off-peak power (€0.1589/kWh).
Limits
- The default price is the French regulated Tarif Bleu on 1 August 2026, Base option 3-6 kVA (€0.2001/kWh incl. tax); the "Off-peak" button applies €0.1589 (€0.2142 peak). If your contract differs, enter its price.
- A fridge does not run at full power around the clock: its compressor cycles. With 8 hours a day the result (350 kWh) is closer to the energy label.
- The standing charge is not included; the 55 g CO₂/kWh factor is an indicative, unverified value.
An appliance you add by hand can have a standby draw: it is counted over the hours the device is not in use (8,760 h minus hours per day × days per year). A 350 W PC used 5 h a day on 364 days, with 5 W of standby, uses 671.7 kWh a year, 34.7 kWh of it on standby (€8.68 at €0.25/kWh).
Sources and dates: French Tarif Bleu prices incl. tax on 01/08/2026, Base option 3-6 kVA and off-peak option, published by EDF following CRE deliberation 2026-147. Checked on 22/10/2026.
Frequently Asked Questions
Which appliance uses the most electricity at home?
In the default list, the 200-litre electric water heater comes first with 3,212 kWh a year, more than half of the 6,098 kWh total. The heater (1,260 kWh) and the fridge-freezer follow.
How much does an electric water heater cost to run per year?
A 2,200 W water heater running 4 hours a day uses 3,212 kWh a year. At the French regulated rate of August 2026, that is about €643 on the Base option (€0.2001/kWh) and €510 on off-peak power (€0.1589/kWh).
What price per kWh should I enter?
Use the price on your bill. From 1 August 2026, the French regulated Tarif Bleu is €0.2001/kWh incl. tax on the Base option (3-6 kVA), €0.2142 peak and €0.1589 off-peak; the tool uses the Base price by default.
How does the tool calculate the CO₂ of my consumption?
It multiplies kWh by a carbon intensity, 55 g CO₂/kWh by default for the French mix. For 6,098 kWh that is about 335 kg of CO₂ a year; you can enter another factor for another country.
How do I calculate an appliance's electricity use?
Multiply its power in watts by its annual hours of use, then divide by 1,000 to get kWh. A 350 W device used 5 hours a day on 364 days runs 1,820 hours and consumes 637 kWh a year.
How much does standby power cost?
Enter the standby power when you add the appliance: the tool counts it over the hours the device is not in use. 5 W of standby over 6,940 hours is 34.7 kWh a year, or €8.68 at €0.25/kWh. Across ten or so devices, standby can exceed €80 a year.
How much electricity does a gaming PC use per year?
With 350 W, 5 hours a day on 364 days and 5 W of standby, the tool finds 671.7 kWh a year, i.e. €134.41 at the French regulated Base rate of August 2026 (€0.2001/kWh) or €167.93 at €0.25/kWh.
Is this tool really free?
Yes, all tools on Kristools are 100% free and accessible without registration.
Is my data protected?
Yes. All processing is performed directly and securely inside your browser. No personal data is sent to our servers.