Having cooking pots with tight-fitting lids allows maximum energy and time efficiency. Without the heat spilling out, the contents of the pot will cook faster and more evenly. For foods like rice, where it is necessary to keep them at a slow simmer for a prolonged period of time without letting steam out, a properly sized lid is a must-have.
Place the pot on a flat, level surface.
Measure the rim of the pot, starting from the inside of the rim and going directly across the diameter. Take the final measurement from the outside of the pot's rim.
Note the measurement of the diameter of the pot and buy a lid that correlates to that measurement.
You can buy a universal lid, with several rings of ridges, that fits a variety of sizes of cooking pots.