How to Convert International Recipes to US Measurements

It is tempting to think of this as metric versus American. There are really three conventions in wide use, and the third catches people out because it looks metric.

The United States measures by volume in cups, tablespoons and teaspoons, defined from the fluid ounce. A US teaspoon is 4.93 mL, a tablespoon 14.79 mL, a cup 237 mL.

Britain and continental Europe measure dry ingredients by weight and liquids by millilitres. Spoons appear only for small quantities and are 5 mL and 15 mL. British recipes almost never use cups, and when they do they mean something historical you should ignore in favour of the weights given alongside.

Australia and New Zealand use metric cups of 250 mL and — this is the trap — a tablespoon of 20 mL, which is four teaspoons rather than three. Everything else looks identical to European practice, so the tablespoon slips through unnoticed.

A metric teaspoon is 5 mL against the US 4.93 mL, a difference of 1.4%. On a teaspoon of table salt that is 0.09 g. No spoon, and no cook, can resolve that. Use your own teaspoons for any recipe from Britain, Europe, Canada or most of Asia and nothing will go wrong.

The metric tablespoon at 15 mL against the US 14.79 mL is a 1.4% difference. Also ignorable.

The Australian tablespoon is not. At 20 mL it is 35% larger than a US tablespoon. Where an Australian recipe says one tablespoon, use 4.1 US teaspoons — call it 1 tablespoon plus 1 teaspoon. On something like baking soda that is the difference between 14.4 g and 19.5 g.

A metric cup is 250 mL and a US cup is 236.6 mL — the metric one is 5.7% larger. Unlike the spoons, this is worth correcting, because cups carry the bulk ingredients and the error scales with them.

Two metric cups of flour is roughly 264 g. Two US cups is 250 g. That gap of about 14 g is close to two extra tablespoons of flour, and it grows with every cup the recipe calls for.

The clean way to handle any cup-based recipe from outside the US is to leave cups behind entirely: convert each cup measure to grams using the appropriate cup size, then work in grams. A metric cup of granulated sugar is about 213 g; a US cup is 202 g.

Old British recipes may use an imperial cup of 284 mL, and very old ones use pounds and ounces. Both are rare enough that the weights given alongside are the safer route.

Dried yeast is sold in sachets sized to a standard loaf, and the standard loaf is not the same everywhere. That makes converting yeast grams to teaspoons the single most common question on an international recipe.

Converting the numbers is mechanical. Converting the ingredients requires knowing what the words mean where the recipe was written.

Bicarbonate of soda is baking soda — 4.8 g per teaspoon. Baking powder is baking powder everywhere, 4.0 g per teaspoon, but British baking powder is often single-acting where American is double-acting, which changes when the lift happens rather than how much there is.

Caster sugar is a fine granulated sugar with no direct US equivalent; granulated works, and superfine is closer. Icing sugar is powdered or confectioners' sugar at 2.5 g per teaspoon. Demerara and muscovado are not the same as American brown sugar, which is refined sugar with molasses added back at 4.6 g per packed teaspoon.

Plain flour is all-purpose flour, 2.6 g per spooned teaspoon. Strong or bread flour has more protein than US all-purpose. Self-raising flour is plain flour with baking powder and salt already in it — about 8.0 g of baking powder per 150 g of flour — so substituting all-purpose means adding leavening back.

Cornflour in Britain is cornstarch at 2.5 g per teaspoon, not American cornmeal. Double cream, single cream and whipping cream differ in fat content from their US counterparts, and that changes how they behave under heat.

Take a French brioche recipe: 500 g farine, 1 sachet de levure de boulanger (11 g), 10 g de sel, 50 g de sucre, 250 g de beurre. Nothing here is in spoons, which is the easy case, but an American kitchen still needs it in terms it can act on.

The flour, butter and sugar are already weights and should stay weights — 4.0 cups of flour is a number you can compute but should not use, because the cup reintroduces the packing error the original recipe never had.

The salt and yeast are the ones worth converting to spoons, because they are small enough that a 1 g scale cannot resolve them well. 10 g of salt is 1.67 teaspoons of fine table salt, 2.08 of Morton kosher, or 3.57 of Diamond Crystal — the same weight of salt, three very different spoon counts.

The 11 g sachet is 3.55 teaspoons of active dry yeast or 3.33 of instant. Note that the recipe assumes a 1 kg-of-flour sachet used on 500 g of flour, which is a deliberately fast rise; if you want the slower ferment an American brioche recipe would specify, that is a recipe decision and not a conversion.

Sugar at 50 g is 11.9 teaspoons, which is 4.0 tablespoons — comfortably in scale territory. Butter at 250 g is just over two US sticks. And "farine" means French T55, which is closer to US all-purpose than to bread flour, so no substitution is needed.

Three last things travel with the recipe and none of them are volume conversions.

Oven temperatures in Celsius convert by the usual arithmetic, but check whether the recipe means a fan oven. A fan runs roughly 20°C hotter in effect than the same dial number on a conventional oven, so a British recipe at 180°C fan is about 200°C conventional, or 390°F. Gas marks are a separate scale again: gas 4 is 180°C, gas 6 is 200°C.

Tin sizes come in centimetres. A 20 cm round tin is 8 inches, 23 cm is 9 inches. The two are not interchangeable — the larger has about 27% more base area, so the same batter bakes shallower and faster.

And flour protein differs by country in ways no conversion table captures. If a European bread recipe comes out slack in an American kitchen, the hydration is the thing to adjust, not the measurement.