UK Baking Units — The Complete Guide

British recipes are a strange mix. One cookbook measures flour in grams, the next one in ounces. Your oven speaks Gas Mark, while a newer recipe might say 180°C or "fan 160". It's not you — the UK genuinely never finished switching to metric, so bakers here juggle three systems at once. Once you know the handful of conversions below, the confusion goes away.

Most serious British bakers weigh flour and butter rather than scooping by cup, because a cup of flour can vary by a third depending on how firmly you pack it. The two units you'll actually meet are grams (g) and ounces (oz). One ounce is 28.35 grams, so a 4 oz block of butter is about 113 g, and 250 g of flour is about 8.8 oz. Older British books lean imperial, newer ones metric, and most books printed since the 1980s give both. If a recipe only lists ounces, multiply by 28 to get grams.

Volume is where the UK and the US really part ways, and the cup is the main difference. A UK cup is 284 ml, but a US cup is only 237 ml — about 17% smaller. Bake an American recipe with a UK cup and you'll end up short on every liquid. A tablespoon (tbsp) is 15 ml and a teaspoon (tsp) is 5 ml in both countries, which is the same, but "1 cup" is the unit that differs. To convert millilitres to UK cups, divide by 284: 500 ml is about 1.76 UK cups. And if a recipe ever says "a mug of milk", be careful — mugs run anywhere from 250 ml to 400 ml, so they are not a measuring tool.

Gas Mark is a UK-only oven scale running from 1 to 10, and each number maps to a fixed temperature. Gas Mark 1 is 140°C, Gas Mark 4 is 180°C (the classic baking temperature), and Gas Mark 6 is 200°C, good for roasting. Fan ovens run 20°C cooler, so a recipe that says "180°C fan" means set a fan oven to 160°C. Most of Europe uses Celsius and the US uses Fahrenheit, so when a British recipe says "Gas Mark 5" and you have a digital oven, a quick converter beats trying to remember the table.