Add your appliances, set your electricity rate, and get your real daily, monthly, and yearly consumption — plus which appliances are actually driving your bill. Everything runs in your browser; your data stays on your device and is saved automatically so you can come back to it.
1 · Your electricity rate
Presets are national averages — check your bill and edit the tariff for accuracy.
2 · Add your appliances
3 · Your appliance list
| Appliance | Watts | Qty | Hrs/day | Days/mo | kWh/mo | Cost/mo | % | |
|---|---|---|---|---|---|---|---|---|
| Nothing added yet — pick appliances above to start. | ||||||||
4 · Your results
Where your bill goes
Add appliances to see the breakdown.
Energy-saving recommendations
- Tips appear once we can see your usage pattern.
Your list auto-saves in this browser.
Understanding your electricity bill — the 3-minute version
What is a watt?
A watt (W) measures how fast a device uses energy — think of it as the "speed" of consumption. A 9W LED bulb sips slowly; a 2,000W induction cooktop gulps. The wattage is printed on a label or power brick on almost every appliance you own.
What is a kilowatt-hour (kWh)?
A kilowatt-hour is the "distance traveled" — energy used over time. Run 1,000 watts for one hour and you've used exactly 1 kWh. It's the unit your utility actually bills you for: watts × hours ÷ 1,000 = kWh. A 100W TV running 5 hours uses 0.5 kWh.
How your bill is calculated
Your monthly bill is essentially: total kWh used × your tariff rate, plus fixed charges and taxes. Many utilities use slab or time-of-use pricing — the more you use (or the worse you time it), the higher the per-unit rate. That's why the calculator above shows percentage contribution: cutting the top one or two appliances usually beats trimming ten small ones.
The five moves that actually lower a power bill
In order of typical impact: switch non-inverter ACs and old refrigerators to inverter models (30–50% cuts on your biggest loads); attack heat — water heaters, dryers, and space heaters convert electricity to heat, the most expensive thing electricity does; shift laundry and EV charging to off-peak windows if your utility prices by time; kill standby clusters with smart power strips; and replace any remaining CFL or tube lighting with LED. Everything else is decoration.
Frequently asked questions
How accurate is this calculator?
The wattages are realistic averages for each appliance class, and every value is editable — check your appliance's label or power brick and enter the exact number for the tightest estimate. Refrigerators and freezers are entered as compressor-averaged draw, which is why they show lower watts than their label. Actual bills also include fixed charges and taxes the calculator can't see.
Where does my data go?
Nowhere. The calculator runs entirely in your browser — nothing is uploaded. Your list is saved in your own browser's local storage, and share links encode the data in the link itself.
Why is my refrigerator's wattage lower than its label?
Fridge compressors cycle on and off — a fridge labeled 150–200W typically averages 50–80W across a full day. We use the averaged figure with 24 hrs/day, which matches how utilities actually see it.
How is the carbon footprint estimated?
Yearly kWh × your region's grid emission factor (kg CO₂ per kWh). Grids differ hugely — Canada's hydro-heavy grid emits ~0.12 kg/kWh while coal-heavy grids exceed 0.7 — so pick your region preset for a realistic figure.
Can this size a solar or battery backup system?
It's the perfect first step — your daily kWh figure is exactly what solar and battery sizing starts from. Our off-grid sizing guides take that number and turn it into panel wattage and battery capacity.