Energy Audit

Home Energy Bill Calculator

Break your monthly electricity bill down by appliance -- AC, water heating, fridge, laundry, lighting, electronics and EV charging -- and see exactly where your biggest costs come from.

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Home Energy Bill Calculator
Estimate your monthly electricity and gas costs by appliance usage

Monthly Appliance Usage:

Est. Monthly Bill
โ€”
Electricity Usageโ€”
Electricity Costโ€”
Largest Consumerโ€”
Annual Billโ€”
Cost per Dayโ€”
Avg Household (UK/AU)~$120โ€“160/mo

Disclaimer. Energy usage estimates use typical appliance power ratings and are only as accurate as the hours and wattages you enter; actual bills vary by appliance efficiency, climate, tariff structure and utility fees not modeled here. Read full disclaimer →

About Home Energy Audit

A home energy audit identifies where you are losing energy and where improvements give the best return on investment. Typical home energy breakdown: air conditioning and heating 35-45%, water heating 15-20%, lighting 10-15%, appliances 15-25%, standby power 5-10%. Air conditioning is the biggest opportunity since a 5-star BEE-rated inverter AC uses 30-50% less electricity than a 2-star non-inverter model.

Quick wins with good payback: replace old lights with LEDs (90% energy savings); install a 5-star inverter AC; add ceiling fans allowing the AC thermostat to be set 4 degrees higher saving 16-20% on cooling; seal air leaks around doors and windows; set water heater to 48 degrees instead of 60 degrees; install a solar water heater replacing 80% of water heating electricity. Every 1 degree increase in AC thermostat setting saves approximately 6% on cooling energy bills.

Formula Used In This Calculator

Each appliance's monthly kWh is estimated from typical power draw: AC/Heating = hours/day × power (kW) × 30 days; Water Heater = hours/day × 3 kW (assumed) × 30 days; Fridge = power (kW) × 24 hours × 30 days (runs continuously); Washing Machine = loads/week × 4 × 1.2 kWh per load; Lighting = hours/day × 0.04 kW × 10 bulbs (assumed) × 30 days; TV/Electronics = hours/day × 0.1 kW (100W assumed) × 30 days; plus any EV charging kWh entered directly. All components sum to total monthly kWh, multiplied by your electricity rate for your monthly bill, then ×12 for an annual estimate.

Frequently Asked Questions

It assumes a 3 kW water heater, 10 bulbs at 40W each for lighting, 100W for TV/electronics, and lets you enter your actual AC power and fridge wattage since those vary the most between households. Washing machine usage is estimated at 1.2 kWh per load. These are reasonable planning defaults, but your actual appliance wattages (check the nameplate or spec sheet) will give a more precise estimate.
The calculator highlights your single largest consumer based on your entered usage, but according to the accompanying breakdown, air conditioning and heating typically account for 35-45% of a home's electricity use, making it usually the biggest opportunity for savings -- especially with an efficient inverter AC unit.
As a general rule of thumb cited in this calculator's notes, every 1-degree increase in your AC thermostat setting saves approximately 6% on cooling energy costs, and using ceiling fans to allow a 4-degree higher setting can save 16-20% on cooling specifically.
This calculator only estimates the appliances you enter and uses simplified average power ratings -- your actual bill may include additional fixed charges, taxes, tiered/time-of-use pricing, or appliances not listed here (like pool pumps or electric ovens). Use it as a directional estimate for finding your biggest savings opportunities, not an exact bill prediction.
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