The Practical Kitchen Conversions Guide
Cooking measurements look universal until a recipe crosses a border. An American recipe's "1 cup flour" meets a European kitchen that owns a scale and a 250 ml cup, and suddenly a simple cake becomes a translation exercise. This guide explains the systems behind kitchen measurement so any recipe, from anywhere, makes sense — and links to our Cups to Grams Converter for the actual numbers.
Not all cups are the same cup
The word "cup" hides at least five different volumes. The US customary cup — the one in American recipes — is 236.588 ml. US nutrition labels legally use a rounder 240 ml. Australia and most metric-cup countries use 250 ml. Old British imperial cups were 284 ml, and Japanese cups are just 200 ml. The gap between a US and a metric cup is nearly 6% — enough to matter in bread and pastry. When a recipe doesn't say which cup it means, its country of origin is your best clue.
Why grams beat cups for baking
Volume measures how much space an ingredient fills; weight measures how much of it there actually is. Flour is compressible, so the same cup can hold anywhere from roughly 110 g (sifted) to 160 g (scooped and packed) — a swing large enough to turn one recipe into two different outcomes. A digital scale removes the guesswork entirely, which is why professional kitchens and serious home bakers weigh nearly everything. Even the reference standards differ slightly: King Arthur Baking defines a cup of all-purpose flour as 120 g, while USDA FoodData Central lists about 125 g. Both are valid; consistency within a recipe is what counts.
The spoon-and-level technique
If you do measure flour by cup, the technique matters more than the cup: fluff the flour first, spoon it lightly into the cup without tapping or shaking, then level the top with a straight edge. Dipping the cup straight into the bag compacts the flour and can add 20–30% extra — the single most common cause of dry, dense home baking.
Oven temperatures across systems
Recipes state heat in Fahrenheit (US), Celsius (most of the world) or gas marks (UK). The common anchors: 325°F ≈ 160°C ≈ gas mark 3; 350°F ≈ 180°C ≈ gas mark 4; 375°F ≈ 190°C ≈ gas mark 5; 400°F ≈ 200°C ≈ gas mark 6; 425°F ≈ 220°C ≈ gas mark 7. Fan (convection) ovens run effectively hotter — the usual adjustment is to reduce the stated temperature by about 20°C (roughly 25°F) or shorten the time.
Butter, sticks and tablespoons
American recipes measure butter in sticks: one stick is ½ cup, 8 tablespoons, 4 ounces, or about 113 g. Two sticks make the classic "1 cup butter" — about 227 g. A US tablespoon is 3 teaspoons (about 15 ml); note that an Australian tablespoon is 20 ml, another quiet trap in translated recipes.
When precision matters — and when it doesn't
Soups, stews and most stovetop cooking forgive loose measurement happily. Baking does not: bread, cakes and pastry are chemistry, where ratios of flour, liquid, fat and leavening decide the outcome. The practical rule: weigh for baking, eyeball for cooking, and when scaling a recipe up or down, use our Recipe Scaler so the ratios move together.