“I looked,” I said. “I can’t find one.”

Suzen turned and looked at me. She began to say, “That’s a load of …” But she stopped. “I’ll look,” she said. “We have one.”

“Oh, I know we have one, Suzen. I just don’t know where.”

We needed an 8” square pan. We were in our Olive kitchen and we could not find that pan there. We both searched the Olive basement, too, but it wasn’t there either. Which meant, since we do have that pan, it must be in our Tribeca kitchen. Or, it was in the Tribeca basement. Both of those were 120 miles away.

It is easy to calculate that an 8” square pan has 64 square inches. It is a little less easy to determine that a 9” round pan has 63.6 inches. So we could substitute. And that is what we did.

It works going up and down, too. A 7” square pan is 49 square inches while an 8” round is 50.2. A 9” square pan is 81 square inches while a 10” round is 78.5 square inches.

It is an easy rule to remember, for common sizes, if you need a pan that is N x N inches, then get a round one that is N+1 inches in diameter.

It’s close enough for government work. If you are using the pan for baking, be sure to check early and often. Your baking time will be affected by a minute or two.