Convert between cups, tablespoons, teaspoons, grams, ounces, and milliliters for baking and cooking.
Cooking uses two measurement systems: U.S. customary (cups, tablespoons, teaspoons, fluid ounces) and metric (milliliters, liters, grams). The U.S. system is volume-based, which works well for liquids but introduces inconsistency with dry ingredients. A cup of flour can weigh between 120 and 150 grams depending on how it is scooped. Professional bakers and most international recipes use weight (grams) for dry ingredients to eliminate this variability.
Fluid ounces and ounces by weight are not the same unit. Eight fluid ounces of water weighs about 8.3 ounces by weight. For water and milk, the difference is negligible. For denser liquids like honey or lighter ones like oil, the discrepancy matters more. Honey weighs about 12 ounces per cup (8 fl oz), while oil weighs about 7.5 ounces per cup. This calculator converts between volume and weight using standard densities for common ingredients.
Butter has its own convention in U.S. recipes: one stick equals 8 tablespoons, 4 ounces, or half a cup. European recipes typically call for butter by weight in grams. Eggs are measured by count in most recipes, but large-batch baking sometimes calls for eggs by weight (one large egg weighs approximately 50 grams, with the yolk at 18 grams and the white at 30 grams).
To double a recipe, multiply all ingredient quantities by two. To halve it, divide by two. This works straightforwardly for most ingredients. However, leavening agents (baking soda, baking powder, yeast) do not always scale linearly. When doubling a recipe, use about 1.5 to 1.75 times the original leavening amount rather than a full double. Spices and salt should also be scaled conservatively and adjusted to taste, especially when increasing a recipe by more than 2x.
Cooking times do not scale proportionally with recipe size. A doubled casserole in a larger pan may need 25 to 50% more time, not double. Temperature usually stays the same. For baked goods, it is often better to bake two batches in the original pan size rather than one batch in a larger pan, since the original recipe was tested at that specific volume-to-surface-area ratio.
The standard U.S. cup is 236.6 mL, but Australian cups are 250 mL, and Japanese cups are 200 mL. British recipes may use imperial measurements where 1 imperial pint equals 568 mL (compared to 473 mL for a U.S. pint). When following recipes from other countries, verify which measurement system is being used before converting. A "tablespoon" is 15 mL in the U.S., UK, and most countries, but 20 mL in Australia. These differences are small for casual cooking but can affect baking precision where ratios matter.
Temperature conversions between Fahrenheit and Celsius are another common source of error. The formula is: Celsius = (Fahrenheit - 32) x 5/9. Common reference points: 350 degrees F = 177 degrees C, 375 degrees F = 190 degrees C, 400 degrees F = 204 degrees C, 425 degrees F = 218 degrees C. Gas mark settings used in British recipes correspond to specific Fahrenheit ranges (Gas Mark 4 = 350 degrees F, Gas Mark 6 = 400 degrees F).