8 oz to mL: What a Standard US Cup Really Holds

What 8 oz to mL Means in American Kitchens

Eight fluid ounces is the single most important volume in American cooking, because it is the size of one standard US cup. Every measuring cup in a US kitchen, every coffee mug, and most recipe instructions trace back to that 8-ounce reference. But the moment you cook from an international recipe or read a product label, that familiar figure turns into milliliters. Converting 8 oz to mL keeps your baking and cooking accurate across both systems.

The answer is 236.59 mL. That number is the bridge between the US cup and the metric system, and it shows up on nutrition labels, import packaging, and European recipes. Our fluid ounces to mL converter gives you the figure instantly, but understanding the math helps you adapt any recipe with confidence.

The 8 oz to mL Formula

The conversion rests on one fixed value: one US fluid ounce equals 29.5735 milliliters. Because fluid ounces and milliliters are both units of volume, the conversion is a simple multiplication. You multiply the number of fluid ounces by 29.5735 to get the equivalent in milliliters.

8 oz Compared With Familiar Containers

Putting 236.59 mL next to common items makes the size click. Eight fluid ounces equals exactly one US cup, 16 US tablespoons, 48 US teaspoons, or half a US pint. Those fractions matter in baking, where 8 oz of milk or water is the foundation of countless recipes.

Practical Uses for the 8 oz to mL Conversion

The conversion matters most when you adapt recipes. If a European recipe calls for 240 mL of milk and your measuring cup is in fluid ounces, you know that 8 oz (236.59 mL) is just shy of the target, so you add a splash more. The same logic applies to water, broth, oil, and any liquid an international recipe lists in milliliters.

It also helps with portion control and hydration. An 8-ounce glass of water is 236.59 mL, so hitting a daily goal of 2 liters means drinking about eight and a half 8-ounce glasses. For packaged drinks, an 8-ounce serving size on a US nutrition label equals 236.59 mL, which lets you compare with metric-labeled imports directly. Coffee makers often mark a cup as 5 or 6 ounces rather than a full 8, so check the carafe before you assume a 12-cup pot holds 12 standard 8-ounce cups. For the next size up, see our guide to converting 16 oz to mL.

Converting 8 oz to Other US and Metric Units

Sometimes milliliters are not the most useful reference. Eight fluid ounces also equals 1 US cup, 0.5 US pints, 0.25 US quarts, or 0.0625 US gallons. In metric units beyond milliliters, it is 0.23659 liters. That is just under a quarter of a liter, which is why a 1-liter bottle pours about four and a quarter 8-ounce servings, a useful ratio for portioning drinks at a table.

For dry ingredients, remember that 8 ounces by weight is different from 8 fluid ounces by volume. Eight fluid ounces of water happens to weigh about 8 ounces, but 8 fluid ounces of flour weighs far less than 8 ounces. When a recipe says 8 oz, check whether it means weight or volume before you measure. To move between cups and milliliters for any value, our cups to mL converter handles the full range.

A Note on the US Cup Definition

The US legal cup, used for nutrition labeling, is defined as 240 mL, which is slightly larger than the customary 236.59 mL cup. This is why some packaged foods list a serving as 240 mL while your measuring cup reads 8 ounces. The difference of about 3.4 mL is small enough to ignore in most home cooking, but it matters in precise baking or when scaling recipes for production.

Knowing both definitions helps you read labels accurately. When a recipe or label says one cup, assume 236.59 mL for home cooking and 240 mL for nutrition facts. Either way, 8 fluid ounces remains the everyday kitchen reference that ties American volume measurements to the metric system used by the rest of the world. When you bake by weight instead, remember that 8 fluid ounces of water is about 236 grams, a useful cross-check.