Microwave Wattage Converter

Adjust microwave cooking time when your oven's wattage differs from the recipe or package.

Recipe / package wattage	1,100 W
Recipe time (m:ss)	3:00
Your microwave's wattage	800 W

Recipe / package wattage

Recipe time (m:ss)

Your microwave's wattage

Cook for about

4:10

248 seconds at 800 W. Microwaves vary, so check the food is piping hot (75 °C / 165 °F) in the centre and stir or rest as directed.

About the Microwave Wattage Converter

A microwave's wattage is its cooking power. If yours is weaker than the package assumes, food needs longer, roughly in proportion: time × package watts ÷ your watts. The wattage is usually on a label inside the door or on the back. Food safety agencies advise heating leftovers until steaming hot throughout, 75 °C (165 °F).

The formula

New time = recipe time × recipe watts ÷ your watts

Worked example

Example: Cook for about = 4:05

Inputs: Recipe / package wattage: 1,200 W; Recipe time (m:ss): 3:00; Your microwave's wattage: 880 W.
Formula: New time = recipe time × recipe watts ÷ your watts
Result: Cook for about = 4:05

Questions people ask

My microwave has no label. How do I tell?

Time how long 1 cup of water takes to boil: under 2 minutes ≈ 1,000 W+, 2–3 minutes ≈ 800 W, over 3 ≈ 600 W.

Is it exactly proportional?

Not quite, so check and add 15–30 s if needed.