How Does a Microwave Heat?
Microwaves heat food by rotating the polar molecules inside through electromagnetic waves, producing heat through friction — a process called dipolar polarization. The microwave emits EM waves at ≈2.45 GHz and is rated in watts (W): the higher the wattage, the more energy it transmits per second.
How Do I Convert Microwave Cooking Times?
Because energy delivered equals power × time, two microwaves of different wattages deliver the same energy when:
New time = (Label time × Label wattage) ÷ Your microwave wattage
For example, if a recipe says 3 minutes at 800 W and your microwave is 1000 W:
New time = (180 s × 800) ÷ 1000 = 144 seconds (2 min 24 sec)
Using the Microwave Wattage Converter
- Check the food packaging for the wattage used and the cooking time.
- Select your time format — min : sec (American/Imperial) or seconds only (metric).
- Enter the food label's cooking time and wattage in the Food Label Info section.
- Choose your microwave's wattage in the Your Microwave section.
- Optionally enable the Conversion Chart to see adjusted times for a range of preset durations.
- Click Convert Cooking Time to get your result instantly.
Important Notes on Wattage
- If your microwave has higher wattage than the label, your food cooks faster — consider reducing the power level to 70–80% to avoid uneven cooking.
- Microwaves do not heat food uniformly; hot and cold spots form due to standing EM waves. The turntable helps, but stirring midway is still recommended.
- Common microwave wattages: 600 W, 700 W, 800 W, 900 W, 1000 W, 1100 W, 1200 W.
FAQs
How do I find my microwave's wattage?
Check the label on the exterior or interior of the door. If not visible, consult the product manual or search the model number online.
Does wattage affect food quality?
Higher wattage heats faster but can create uneven results if not managed. Lower wattage is gentler and more even but takes longer.
Can I use this for any type of food?
Yes. The formula applies to all microwave-safe foods. However, dense or thick foods may still need extra time regardless of wattage, as microwaves only penetrate a few centimeters.