The main difference between a 10 and 12-inch mattress is the height. The larger height tends to mean more of a plush feel. Whereas a thinner mattress tends to be firmer. While the major difference between 10 and 12-inch mattresses is a mere two inches, firmness is another factor that may come into play in your decision. Mattress companies measure the feel and firmness of mattresses using a system called the Firmness Scale, rating beds from 1 to 10. One is the softest, and ten is the firmest. These are further subdivided into levels: Soft
Medium-firm
Firm
There is no one-size-fits-all formula for what is considered comfortable. It depends on the sleeper, whether they prefer a firm vs medium mattress, or something softer. For instance, someone who suffers from back pain may want a mattress of medium firmness, which will offer better support and pain relief.  Typically, thicker mattresses offer better support and pain relief compared to thinner mattresses. If you opt for a 12-inch mattress over a 10-inch one, you’ll get extra cushioning that may feel more comfortable when you sleep.