Most kitchen drawers contain two types of measuring cups — a set of nested cups for dry ingredients and a graduated jug for liquids. They're not interchangeable, and using the wrong one is a surprisingly common source of measurement error.
Dry Measuring Cups
Dry measuring cups (usually a set of 1/4, 1/3, 1/2, and 1 cup) are designed to be overfilled and then levelled off with a straight edge. This is only possible because you can heap the ingredient above the rim before levelling.
Use for: Flour, sugar, cornstarch, oats, cocoa powder, shredded coconut, and any other solid or granular ingredient.
How to use: Spoon the ingredient in, heap it slightly, then sweep a straight edge (like the back of a knife) across the top to remove the excess.
Liquid Measuring Cups
Liquid measuring cups are clear jugs with measurement lines below the rim — designed so you can fill them and read the measurement accurately at eye level without liquid spilling over.
Use for: Water, milk, oil, honey, maple syrup, vinegar, and any pourable liquid.
How to use: Place on a flat surface, pour in the liquid, bend down so your eyes are level with the measurement line, and read the bottom of the meniscus (the curved surface of the liquid).
Why You Can't Swap Them
- Measuring liquid in a dry cup: You have to fill it to the very brim to get a full cup, and any motion causes spills. Difficult to read accurately.
- Measuring dry ingredients in a liquid jug: You can't level off the top, so you end up estimating. The result is rarely accurate.
The Volume Is the Same
Both types measure the same volume — 1 cup is always 236.6ml. The difference is purely in the design that makes each type easier to measure accurately. For maximum precision, use a kitchen scale to bypass the question entirely.