“Cup” is not one universal volume. Choose the definition that fits the recipe or label you are reading.
| Calculator setting | Volume | How to interpret it |
|---|---|---|
| US customary cup | 236.5882365 mL | The US customary volume used by the homepage’s 8-US-fluid-ounce answer |
| Metric cup | 250 mL | Use when the recipe specifies this metric cup |
| Imperial cup | 284.130625 mL | Use when an Imperial cup is explicitly intended |
| US food-label cup | 240 mL | A food-label convention, kept separate from the customary cup |
Definitions: Unicode CLDR unit conversions; food-label convention: FDA household-measure guidance.
Choose from the recipe, not its language
- Look for a stated capacity. A note such as “250 mL cup” resolves the question directly.
- Use explicit metric quantities when provided. If the author gives a milliliter or gram amount, follow that amount for the corresponding task.
- Read the measurement notes. Check the book’s introduction or the website’s recipe guidance.
- Leave uncertainty visible. If the standard is unknown, avoid presenting a guessed conversion as exact.
A recipe written in English does not automatically use US cups. An Imperial cup setting is also not a claim that every recipe from the UK uses that measure.
An ingredient source cup is a separate case
A food chart may pair a cup portion with a weight without specifying the cup’s capacity. Our ingredient tools call that a source portion. They let you scale the published portion but do not silently identify it with one of the volume standards above.
Try cups to milliliters to compare defined volumes, or read how source portions are handled.