How Much Is 8 oz in Cups?

Quick-reference table for other common amounts

The important caveat — fluid ounces vs. dry (weight) ounces: this exact 8:1 conversion only holds for liquid measurements measured by volume. A dry ounce is a unit of weight, not volume, so "8 oz" of a dry ingredient like flour or shredded cheese doesn't reliably equal 1 cup — it depends on how dense that specific ingredient is. For example, 8 oz of water is 1 cup by volume, but 8 oz of flour by weight is closer to 1.8 cups by volume, since flour is much less dense than water.

Why this mix-up happens so often: US recipes frequently label ingredient amounts in ounces on packaging (a "can of tomatoes, 8 oz") without clarifying whether it's a weight or volume ounce, and many people assume the same 8:1 rule applies everywhere. The rule is reliable for liquids (water, milk, oil, juice) but not for dry goods measured by weight.

Rule of thumb: if a recipe or label says "fl oz" or is describing a liquid, use the 8 oz = 1 cup conversion directly. If it says just "oz" for a dry ingredient, check whether that's a weight measurement and, if precision matters, weigh it on a kitchen scale rather than assuming a cup equivalent.

You may also want How to Measure Hips? or How to Measure Your Inseam?.

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