# Rule of thumb for cooking multiple things in a microwave at the same time?

Is it possible to cook multiple things at the same time in a microwave and how do I adjust the cooking time?

What if the two items are identical, do I double the time or multiply it by some other factor?

What if the two items are different and have different individual cooking times?

• I guess, a good dynamic programming algorithm would solve this. – TJ- Oct 11 '12 at 13:02

For different food types there is no single correct answer, as it is very dependent on the specific microwave energy absorption and reflectance characteristics of each item (food and container) in the microwave oven

It's possible to put one item in which has a high absorbency and one with a low absorbency, and to have one fully cooked and the other still cold

e.g. A potato placed in a ceramic bowl, and a sausage on a glass plate, would result in a hot sausage, and a cold potato (assuming the sausage and potato are of the same weight)

For similar food types a general multiplication is required, but not exactly by weight, as each microwave oven has an 'efficiency to food and weight' exponential curve. You will find the result of this out by experience with the oven. This rule applies somewhat to normal thermal convection ovens too

e.g. 250 g of potato takes 6 minutes in your microwave oven, then 500 g may take 9 minutes not 12 minutes, and 1 Kg may take only 12 minutes, until you reach the equilibrium point of no further improvement (about 1 Kg for my domestic microwave oven)

We enjoy pot pies and when we are in a hurry sometimes put two in the microwave at the same time. Usually it takes 7-8 minutes per pie. If two are in the oven at the same time (same size too) I multiply the time times 1.5. Generally it works out well. Happy cooking.

It's best not to cook two items together because the amount of energy Vs time taken had been worked out by the manufacturer for the given power rating. Remember that temperature can be a factor, and getting to that temperature may take a significant amount of the cooking time to reach. So cooking 2 of the same item together might take longer than doing one after the other. This is probably more obvious with things that are steam cooked as it's going to take longer for the extra mass to heat up. A simple side by side wattage comparison shows that a conventional oven might be rated at 3000 Watts Vs 700 Watts of a microwave

• I am not sure that the wattage of different types of machines can be an argument - the basic principles of ovens and microwaves are totally different. – Stephie Nov 10 '18 at 15:19
• That's total and utter nonsense. You just need to adjust the time - and its non linear but can be done and repeated. – RichieHH Jan 14 '19 at 21:40
• I don’t know, the rest of the answer may be nonsense but the advice “it’s best not to cook two items together” seems sensible. What’s the point of risking having one item come out uncooked and the other overcooked? – Bruno Ely Jul 20 '20 at 21:55