How to Convert Kitchen Measures With Confidence

Use measuring spoons for small amounts, a dry cup for dry ingredients, and a liquid cup on a flat surface for liquids. For quick home cooking, remember 3 teaspoons = 1 tablespoon, 16 tablespoons = 1 cup, and 1 cup is about 237–240 milliliters. When a recipe depends on an ingredient's density, weigh it instead of guessing a grams conversion.

Keep the small units straight

NIST's home-cooking equivalencies give 5 mL for 1 teaspoon, 15 mL for 1 tablespoon, and 240 mL for 1 cup as approximate household values. Its conversion table gives more precise approximations of 4.93 mL, 14.79 mL, and 0.24 liter. The difference is rounding, not a different kitchen system.

For a recipe calling for 2 tablespoons, use 6 teaspoons if the tablespoon measure is missing. For 3/4 cup, use 12 tablespoons. The University of Illinois Extension cooking chart lists 1 cup as 16 tablespoons and 48 teaspoons, and 237 mL in its liquid-measure row.

Match the tool to the ingredient

Dry measuring cups are designed to be filled to the top and leveled. Illinois Extension says to spoon a dry ingredient into the cup, avoid scooping directly from the container, and level the excess with a flat edge. Do not pack, shake, or tap the cup unless the recipe specifically says to pack an ingredient such as brown sugar.

Liquid measuring cups usually have a spout and side markings. Set the cup on a flat surface and read at eye level, as the Illinois guidance recommends. Holding the cup in the air makes the surface harder to read and increases the chance of spilling.

Measuring spoons work for wet and dry ingredients when the amount is small. Fill the spoon as the recipe directs and level it when the instruction calls for a level measure. A kitchen spoon from the drawer is not a standardized measuring spoon.

Convert volume without false precision

NIST calls these home-cooking equivalencies approximate. That matters because cups and spoons measure volume, while grams measure mass. A cup of water and a cup of flour occupy the same volume but do not weigh the same. Even two dry ingredients can pack differently.

If an international recipe gives milliliters, a practical home conversion is 240 mL to 1 US cup, 15 mL to 1 tablespoon, and 5 mL to 1 teaspoon. Keep the recipe's rounding style. Converting 240 mL to “1 cup” is useful; reporting 239.999 mL does not improve a normal kitchen step.

Know when to use a scale

NIST's culinary tips call weighing the safest conversion method when changing a traditional American recipe into grams. Use a scale for flour, sugar, and other ingredients where packing changes the volume. The recipe may provide a grams value; if it does, follow that value rather than replacing it with a generic “one cup equals” number.

Pocket conversion card

• 1 tablespoon = 3 teaspoons = about 15 mL
• 1/4 cup = 4 tablespoons = about 60 mL
• 1/2 cup = 8 tablespoons = about 120 mL
• 1 cup = 16 tablespoons = about 237–240 mL
• 2 cups = 1 pint = about 480 mL

When the recipe is written for a different country's cup or spoon, check its convention before converting. For an ordinary US recipe, use the card, choose the correct measuring tool, and reserve the scale for ingredients whose density makes volume unreliable.