There is no single number for this conversion, because it depends on what you are converting — and that is exactly what this guide is for. One teaspoon of all-purpose flour weighs 2.5 g, one teaspoon of granulated sugar weighs 4.1 g, and one teaspoon of butter weighs 4.7 g. A cup measures volume, not weight, so flour, sugar, butter, honey and oil all give different answers. Below is the full ingredient table from King Arthur Baking and USDA data, worked examples from real recipes, the disputed figures (flour and sugar especially), and when to trust the table and when to reach for a scale.

1 Teaspoon in Grams by ingredient

All figures below are approximate. Densities come from King Arthur Baking and USDA FoodData Central; verify with a kitchen scale when it matters.

Ingredient 1 tsp weighs 3 tsp (1 tbsp) weigh
All-purpose flour 2.5 g 7.5 g
Granulated sugar 4.125 g 12.38 g
Brown sugar (packed) 4.438 g 13.31 g
Powdered sugar 2.354 g 7.062 g
Butter 4.729 g 14.19 g
Honey 7 g 21 g
Milk 5.083 g 15.25 g
Water 4.938 g 14.81 g
Heavy cream 4.958 g 14.88 g
Olive oil 4.5 g 13.5 g
Vegetable oil 4.542 g 13.62 g
Rolled oats 1.854 g 5.562 g
Cocoa powder 1.75 g 5.25 g
Table salt 6 g 18 g
Yogurt 5.104 g 15.31 g

Method and sources

Each number in the table comes from a weighed cup, not from a calculation. King Arthur Baking's ingredient weight chart and USDA FoodData Central both publish grams per US cup (236.6 ml), measured with a stated method: dry ingredients spooned and levelled, brown sugar packed, liquids poured. That method is part of the number — flour spooned and levelled is 120 g, but the same flour scooped straight from the bag can be 130 g or even 142 g, which is the most disputed figure in baking and the reason recipes that say '1 cup of flour' disagree with each other. Sugar has its own smaller dispute: King Arthur lists granulated sugar at 198 g per cup while USDA rounds to 200 g, a 2 g difference that is rounding, not disagreement. Use the method stated, and the numbers will agree with the recipe developer's kitchen; use a different method, and they will not.

Why this conversion comes up

The reason cooks need this page is that recipes disagree with each other. One recipe writes flour in cups, the next in grams; one writes butter in tablespoons, the next in grams; and a cook who owns a scale and a set of cups still has to translate between them several times per recipe. The figures here are the standard reference values — King Arthur Baking for most dry goods, USDA FoodData Central for liquids and dairy — and each one carries its method, so you know whether to spoon and level, pack, or pour.

Worked examples

Doubling a cookie recipe

A cookie recipe calls for 2 teaspoon of Cocoa powder, and you are doubling it: 4 teaspoon, or about 7 g grams. Double the flour and the sugar by weight if you can, because doubling a volume error doubles the error too. If you must use cups, spoon and level every single one — do not scoop, and do not tap the cup down.

A sauce that needs thickening

A sauce recipe calls for 1 teaspoon of Granulated sugar to thicken it. That is about 4.125 g grams. Cornstarch and flour thicken differently — cornstarch needs to be mixed with cold liquid first or it clumps — and the weight matters more than the volume, because a packed tablespoon of starch weighs far more than a level one.

A glaze with powdered sugar

A glaze recipe calls for 2 teaspoon of Cocoa powder. That is about 3.5 g grams. Sift powdered sugar before measuring it: it clumps in the bag, and a cup of unsifted powdered sugar weighs more than a cup of sifted. For a smooth glaze, weigh the sugar if you can and add the liquid a teaspoon at a time.

Practical guidance

The conversion also matters when you cook from two traditions at once. An American recipe, a British cookbook and a metric scale can describe the same dish in three different units, and the dish only works if all three agree. The fixed factor on this page is the bridge between them — but remember to check which pint, quart or gallon the recipe means, because the imperial versions are about 20% larger than the American ones.

Common mistakes to avoid

  1. Scooping flour with the cup instead of spooning and levelling. Scooping flour with the cup instead of spooning and levelling. Scooping compacts the flour and can add 20 g or more per cup — the single most common reason a cake comes out dry. Spoon the flour in, level it off, and never tap the cup down.
  2. Packing brown sugar when the recipe means loose, or leaving it loose when the recipe means packed. Packing brown sugar when the recipe means loose, or leaving it loose when the recipe means packed. Packed brown sugar is 213 g per cup; loosely spooned it is about 170 g. That 43 g gap changes a cookie completely, so pack it firmly unless the recipe says otherwise.
  3. Measuring honey or syrup in a dry cup. Measuring honey or syrup in a dry cup. Sticky liquids cling to the cup and you lose a tablespoon to the sides. Use a liquid jug, or lightly oil the cup first so the honey slides out.
  4. Treating all flours as interchangeable by weight. Treating all flours as interchangeable by weight. Cake flour, bread flour, whole-wheat flour and almond flour all weigh differently per cup, and they behave differently too. Convert with the right row of the table, and do not swap flours cup-for-cup without expecting a different result.

Frequently asked questions

Why is flour listed at 120 g per cup when other sources say 125 g or 130 g?

Because the figure depends on the method. King Arthur Baking lists 120 g per cup spooned and levelled; other sources quote 125 g or 130 g, and a scooped cup can reach 142 g. The difference is not a mistake in any source — it is the difference between spooning flour into the cup and scooping the cup through the bag. Spoon and level, and 120 g is the right figure.

Is granulated sugar 198 g or 200 g per cup?

Both, depending on rounding. King Arthur Baking lists 198 g per cup; USDA FoodData Central rounds to 200 g. The 2 g difference is rounding, not a real disagreement, and it makes no difference in any recipe. Use 198 g if you want the more precise figure.

Can I use these conversions for any ingredient?

Only for the ingredients in the table. Every density is measured individually, so an ingredient that is not listed has no figure here — and this guide does not guess one. If your ingredient is not in the table, weigh it on a scale, or convert it by volume (cups to millilitres) instead, which needs no density at all.

Should I spoon and level, or scoop?

Spoon and level, always, for dry ingredients. Spoon the ingredient into the cup, then level it off with the back of a knife. Scooping with the cup compacts the ingredient and can add 20 g or more of flour per cup — the most common reason a cake comes out dry.

What is the best way to convert a whole recipe?

Convert every ingredient before you start, write the converted amounts in the margin, and then cook without stopping to calculate. If you own a scale, weigh each ingredient directly in the unit the recipe uses — that is more accurate than any conversion table.

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