What GHz do microwaves use?

Microwaves range in frequencies from 100’s of MHz to 100’s of GHz. Presently the frequency bands used for 5G (between 3GHz to 28GHz) fall within this spectrum .

The ITM designated the 2.4 GHz band as an unlicensed spectrum specifically for microwave ovens . This band has three compelling properties: It doesn’t require much power to broadcast, it’s easy to contain, and at relatively lower power it can heat food.11 Oca 2019

Following international conventions, microwave ovens at home or in restaurants operate at frequencies of about 2.45 GHz , i.e. λ = 12.