Using Recipes from Abroad: Converting Ingredients

What actually changes across borders

A recipe from another country can differ in four ways: how ingredients are measured, how heat is described, how big the pan is, and what the units mean. A US recipe measures in cups, tablespoons, ounces and °F. A recipe from continental Europe typically gives grams, millilitres and °C. A British one may use a mix, including gas marks.

The goal of converting is not to produce a long string of decimals. It is to arrive at amounts that you can actually measure and that preserve the ratios between ingredients, because the ratios, more than any single number, make a recipe work.

Step 1: work out which system the recipe uses

Look for clues. Cups, sticks of butter and °F suggest a US recipe. Millilitres, grams and °C suggest a metric one. A tablespoon in a recipe from Australia is 20 mL, not the usual 15 mL, and a cup may be 250 mL rather than 236.6 mL. Fluid ounces and pints could be US or imperial, and the imperial ones are larger.

If the recipe lists both, as many do, prefer the metric weights. They were probably calculated by the author and tested.

Step 2: convert volumes

Liquids convert exactly through millilitres. One US cup is 236.5882365 mL, one tablespoon 14.78676478125 mL and one teaspoon 4.92892159375 mL. So ¾ cup of milk is 177.4 mL, and 2 tablespoons of oil is 29.6 mL. In practice, round to 175 mL and 30 mL.

Going the other way, 250 mL of stock is 1.057 US cups, or one cup plus about a tablespoon. Convert once, round sensibly, and use the rounded numbers everywhere so ratios stay consistent.

In a unit converter such as this one, fractions have to be typed as decimals: ¾ cup is entered as 0.75, and either a dot or a comma works as the decimal mark. Pick the units, read the result, and choose the number of decimal places you want.

Step 3: convert weights, and know the limit

Ounces and pounds convert exactly to grams. A pound is 453.59237 g and an ounce is 28.349523125 g, so 8 oz of cream cheese is 226.8 g. A US stick of butter is ½ cup, 8 tablespoons or 4 oz, about 113 g. If butter is sold by weight where you live, use 113 g per stick rather than counting tablespoons.

What a unit converter cannot do is turn cups of a dry ingredient into grams. That needs a density, and densities depend on the ingredient and how it is packed. One widely used baking chart gives 120 g for a cup of all-purpose flour and 198 g for a cup of granulated sugar; other sources differ. If you want gram quantities for flour, look for the recipe’s own metric version or use a trusted chart and stay with it throughout.

Step 4: convert oven temperatures and pan sizes

For temperature, subtract 32 and multiply by 5/9. A 350 °F oven is 176.7 °C, which recipes usually round to 180 °C; 400 °F is 204.4 °C, usually shown as 200 °C. British recipes may use gas marks, which a converter does not handle. One published table lists gas mark 4 as 350 °F or 180 °C, with the Celsius figures rounded. Ovens differ, and fan ovens often need adjustment, so follow the oven maker’s guidance.

Pan sizes are lengths and convert exactly: one inch is 25.4 mm. A 9-inch round pan is 22.86 cm across, so a 23 cm pan is a close match. A 9 × 13 inch pan is 22.86 × 33.02 cm, close to 23 × 33 cm. Using a pan with a very different area changes depth and baking time, even if the volume is right.

A complete example

Suppose a US recipe reads: 2 cups flour, ½ cup (1 stick) butter, ¾ cup sugar, 1 teaspoon vanilla, bake at 350 °F in a 9-inch round pan.

• Flour: 2 cups, about 240 g using the 120 g chart figure.
• Butter: 1 stick, about 113 g.
• Sugar: ¾ cup, about 149 g using 198 g per cup (148.5 g).
• Vanilla: 1 teaspoon, about 5 mL.
• Oven: 350 °F, which is 176.7 °C, set to 175 or 180 °C.
• Pan: 9 inches, which is 22.9 cm.

Notice that only the flour and sugar rely on an estimated density; everything else is an exact conversion.

Checking your work

Convert back to see whether you get the original. Look at the proportions, too: if the flour-to-butter ratio looks different after conversion, something went wrong. Convert all the amounts first, then cook; do not mix cups and grams in one recipe.

If you also need to change the number of servings, scale after converting: half of 226.8 g of cream cheese is 113.4 g, which is easier to weigh than half of “8 oz”. Scaling first and converting afterwards gives the same result, but converting first keeps the arithmetic simpler.

For anything where an error carries a safety risk, such as preserving, canning or food-safety temperatures, follow the instructions of the original source or an official authority rather than a converted number.