US vs Metric Cups: When It Matters
One of the biggest sources of confusion in home baking is the definition of a "cup." Depending on where your recipe was written, a cup can vary in volume by nearly 20%.
US Standard Cup
240 mL
The legal standard used for nutritional labeling and most modern US recipes.
Metric Cup (UK/AU)
250 mL
Used in most commonwealth countries and increasingly in European home baking.
The Danger Zone
When baking cakes or sensitive pastries, using a 250mL cup for a recipe written for 240mL cups can introduce an excess of flour and sugar that ruins the crumb structure. Always check the source of your recipe.
Our Standard
The Baking Calculator defaults all conversions to the 240 mL US Standard Cupto ensure safety and consistency across the widest range of available tools.