How to Use the Power Calculator
Use this generator power calculator Australia to estimate the total power required for the appliances and tools you plan to run at the same time. It helps you size a generator, battery system, or mains supply more accurately.
Step 1: Choose category and appliance
Use the Category dropdown to choose a group (e.g. Home Appliances, Power Tools, Lighting). Then use the Appliance dropdown to choose a specific item. The list shows each appliance with its typical wattage in brackets.
Step 2: Set wattage basis and add to your list
Use Wattage basis to choose which value is used when you add: Typical (default), Max (for generator sizing), or Min. Click Add to add the selected appliance to Your list. Add the same appliance again if you run more than one (e.g. two fridges).
Step 3: Override watts (optional)
For any row in Your list, type a value into Override (W) if your appliance has a nameplate rating, you’re using a different model, or you want a more accurate estimate.
When an override is entered, the calculator uses that value instead of the typical/min/max from the list.
Step 4: Manage your list
Use Remove to delete a row. Use Clear all to reset the calculator and remove every item.
Step 5: Check totals
The calculator shows:
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Total (typical) W – sum of typical wattage for all items (reference)
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Total (max) W – sum of maximum wattage; use this for generator or inverter sizing
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Total (min) W – sum of minimum wattage (reference)
Add a safety margin (e.g. 10–20%) to the max total when sizing backup power.
Recommended generator
Set Phase (1 or 3), Fuel type (Diesel, Petrol, Gas), and Safety margin (%). The calculator shows kW recommended and example products that meet your load.
24-hour power use graph
The graph shows an estimated load profile from your selections (e.g. morning peaks for kettle/toaster, evening for TV/cooking). Use it to see when demand peaks over the day.
Important note
This calculator provides an estimate. Some equipment has start-up surge (motors, compressors, pumps, fridges, air conditioners). For those loads, use a higher Override (W) value, choose Max as the wattage basis, and/or increase the Safety margin (%) when sizing your generator or inverter.
Domestic Power Load Calculator
Select appliances, add a safety margin, and get a recommended generator size.
How to use this calculator
1. Choose category and appliance, set wattage basis and Qty, then click Add — or use Add custom for equipment not in the list.
2. Use Override (W ea.) for watts per unit. Totals multiply by quantity.
3. Check Total (max) W and the recommended kW below.
Motor/compressor loads may need a higher override or safety margin.
1) Basics
3) Your load
Total (typical)
0
W
Total (min)
0
W
Total (max) — use for sizing
0
W
Recommended generator
—
kW
Add a safety margin (e.g. 10–20%) to the max total when sizing backup power.
2) Add appliances
Choose a category and appliance (set Qty for multiples), or add custom equipment below.
Or add custom equipment
Set Qty for multiples of the same item. Override (W ea.) is watts per unit — totals multiply by quantity.
- No appliances added yet. Select from the list, add custom equipment, or click Add.
4) Recommended generator
Typical domestic power use (24 hours)
Estimated load profile from your selections.
Morning (6–9): toaster, coffee, kettle. Day (9–5): washing, AC, tools. Evening (5–10): TV, cooking, lights. Base (24/7): fridge, router, medical.