Cooking

Microwave Cooking Time Converter

Quickly convert cooking times between 700, 800, 900, 1,000, 1,100 and 1,200 watt microwaves.

Physics-based approximation
1

Your appliance details

Units

No sign-up. Your inputs stay in your browser.

2

Your results

Adjusted cooking time4 min 17 sec
Time change+1 min 17 sec
Power ratio1.43×
Total seconds257 sec

What this means

Use this as a starting time, then stir, rotate and check that the food is heated evenly.

Show calculation
  1. P₁t₁ ≈ P₂t₂
  2. Time = 180 sec × 1,000 W ÷ 700 W = 257.1 sec

Important notes

Use cooking output watts, not electrical input watts.

Efficiency, food shape, water content, container and food distribution affect actual heating.

Always verify doneness with a food thermometer when food safety is involved.

Calculation basis: Physics-based approximation

Use common wattage shortcuts to adapt a package instruction without looking up a conversion chart. This tool shares the same inverse-power calculation as the wattage calculator, with a focus on quick time entry. It scales an existing instruction, rather than creating a new cooking instruction for raw food.

How to use

  1. Choose the original wattage from the package using a shortcut or enter a custom value.
  2. Enter the package duration in minutes and seconds.
  3. Choose your microwave output and use the new time as an estimate, preserving all stirring and standing instructions.

How the calculation works

Formula

Converted seconds = original seconds × original watts ÷ destination watts. Minutes and remaining seconds are formatted from the same result.

Example

Two minutes at 800 W becomes 1 minute 36 seconds at 1,000 W. Two minutes at 1,000 W becomes 2 minutes 30 seconds at 800 W.

Factors affecting the result

  • The relationship is inverse: more cooking power means less calculated time.
  • Small portions and short times may need closer observation than a proportional model suggests.
  • The conversion assumes the same food amount and initial condition.

Frequently asked questions

Can I convert between wattages not shown in the shortcuts?

Yes. Enter custom positive output wattages. The shortcuts are conveniences and do not constrain the equation.

Should I double the time for twice as much food?

This tool does not model changes in portion size. Use instructions for the actual quantity, then convert the stated microwave wattage.

Is the seconds display a guarantee?

No. Seconds help you set the timer, but food heating remains approximate. Follow the original food-safety checks.

Sources & methodology

Calculation basis: Physics-based approximation. Methodology

Last updated: September 15, 2026