The recent thread on measuring spoon accuracy got me wondering about the accuracy of my measuring cups. I have five glass measuring cups: a 4 cup Pyrex, a 2 cup Bennington Flameware, a 1 cup Bennington Flameware, a 1 cup Anchor Hocking, and an ancient 1 cup Pyrex.
Using my digital scale, I tared each cup and filled them with water to various marks. One cup should weigh 8 oz. The results:
Pyrex 4 cup: 1c = 7.3 oz, 2c = 15.4 oz, 3c = 24.5 oz, 4c = 33.2 oz
Flameware 2 cup: 1c = 8.2 oz, 2 c = 17.1 oz
Flameware 1 cup: 1c = 7.4 oz
Anchor Hocking 1 cup: 1c = 8 oz
Pyrex 1 cup: 1c = 7.9 oz
Though none are enough off to throw off a recipe, it is interesting to know the difference between them.