Cooking · wattage

Microwave wattage time converter

Recipe written for a different microwave? Convert the cooking time to your oven's wattage — with stir, rest, and precision warnings.

Adjust for your microwave

min sec
Often printed on the recipe or assumed to be 1000 W.
Check the door, back, or inside the door frame.
Your time
Cook for6 min 15 sec
Original5 min at 1000 W

How wattage changes cooking time

A microwave's power output is measured in watts, and the time to heat food scales inversely with it: a less powerful microwave needs proportionally longer.

new time = original time × (original watts ÷ your watts)

So a recipe written for a 1000 W oven takes 25% longer in an 800 W one. Home microwaves commonly range from about 600 W to 1200 W, which is a big spread — enough to leave food cold or overcooked if you ignore it.

Why this is a guideline, not a guarantee

Microwaves heat unevenly, and food shape, starting temperature, and quantity all matter. Stir or rotate partway through, let food rest a moment after (it keeps cooking), and start a little short — you can always add time. For anything delicate like melting chocolate or butter, don't trust a converted time; use short bursts at reduced power and watch closely.

How do I adjust microwave time for wattage?
Multiply the time by the recipe's wattage divided by yours. A 1000 W recipe in an 800 W microwave takes 1000/800 = 1.25× as long.
Where do I find my microwave's wattage?
Check the label inside the door frame, on the back, or in the manual. Home microwaves usually range from about 600 to 1200 watts.
Can I use this for melting chocolate?
Not reliably. For delicate tasks, heat in short bursts at reduced power and check often — a converted time can scorch them.

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