At the moment I do not have access to one of the many watt to time conversion charts on the internet.

I have an 800 W microwave. The frozen dinner I am preparing says to cook it at 1100 Watts for 6 1/2 minutes.

I punch the 1100 watts for 6 1/2 minutes buttons on the built-in microwave calculator to calculate the additional time it will take to heat the food in a lesser 800 W microwave.

The microwave automatically sets the microwave for the new time as acquired through the calculator.

Edit 2020 3 21: I should have mentioned "Because there are so many variables when it comes to micro-cooking frozen foods, there is not a specific formula or direct ratio for calculating conversion times."[1]

No Algebra required at school [2]

People are bad at math [3]
-- Sunstone, Mar 15 2020

[1] Maybe the proper conversion can only be done by the manufacturer of the microwave? https://www.theeagl...4-e31a9377dfe0.html
[Sunstone, Mar 21 2020]

[2] No algebra required at school to teach you to learn how to think https://duckduckgo....uired&t=ffsb&ia=web
[Sunstone, Mar 21 2020]

[3] Many if not most are bad at math https://duckduckgo....+math&t=ffsb&ia=web
[Sunstone, Mar 21 2020]

6.5 minutes = 390 seconds.

1100/800 = 11/8 = 1.375

390 * 1.375 = 536.5 = 8.93 minutes

No online calculator needed...
-- 8th of 7, Mar 15 2020


Perhaps the microwave oven control panel should be calibrated in whatt-ours instead of seconds? Would that be in joules I suppose?
-- pocmloc, Mar 15 2020


It would be better to calculate a set of conversion factors - in binary, for universal applicability - for each power range; these could then be chiselled onto a small polished granite stele, placed alongside the microwave oven for easy reference.
-- 8th of 7, Mar 15 2020


We guess RFC 1149, "IP over Avian Carriers"
-- 8th of 7, Mar 15 2020


But that does exactly fulfill the criteria for half-bakedness ...
-- 8th of 7, Mar 21 2020


It would have to be a Babbage engine, powered by a Newcomen engine driven by steam from the microwave oven, then. ..
-- 8th of 7, Mar 22 2020


I think you should need to increase the time beyond what the formula says when scaling for a less-powerful microwave oven, and vice versa, because heat loss from the food will take away a larger portion of the input energy at a lower power, due to the heating taking place over a longer time interval. By how much will depend on the food and its shape.
-- notexactly, Mar 22 2020



random, halfbakery