{"schema":"askedwell-answer-v1","url":"https://askedwell.com/pages/how-to-convert/fluid-ounces-to-cups","question":"How many fluid ounces in a cup?","short_answer":"1 US cup = 8 fluid ounces (fl oz). 1 fl oz = 1/8 cup. Common: 4 fl oz = 1/2 cup, 16 fl oz = 2 cups (1 pint), 32 fl oz = 1 quart, 128 fl oz = 1 gallon. Note: US fluid oz ≠ UK fluid oz (28.4 mL ≠ 29.6 mL).","long_answer":"**The conversion (always the same)**\n\n1 US cup = 8 US fluid ounces. The US fluid ounce = 29.5735 mL. The US cup = 236.59 mL (8 × 29.57).\n\n**Quick reference table**\n\n| Fluid ounces | Cups | Pints | Milliliters |\n|---|---|---|---|\n| 1 fl oz | 1/8 cup | 1/16 pint | 29.6 mL |\n| 2 fl oz | 1/4 cup | 1/8 pint | 59.1 mL |\n| 4 fl oz | 1/2 cup | 1/4 pint | 118.3 mL |\n| 6 fl oz | 3/4 cup | 3/8 pint | 177.4 mL |\n| 8 fl oz | 1 cup | 1/2 pint | 236.6 mL |\n| 16 fl oz | 2 cups | 1 pint | 473.2 mL |\n| 32 fl oz | 4 cups | 2 pints (1 qt) | 946.4 mL |\n| 128 fl oz | 16 cups | 8 pints (1 gal) | 3,785 mL (≈ 3.79 L) |\n\n**US fluid oz vs UK fluid oz (where confusion happens)**\n\n| Standard | Fluid ounce (mL) | Cup (mL) | Pint (mL) |\n|---|---|---|---|\n| US customary | 29.57 | 236.6 (8 fl oz) | 473.2 (16 fl oz) |\n| US legal (FDA nutrition labels) | 30 (exact) | 240 (8 fl oz × 30) | 480 |\n| UK imperial | 28.41 | 284.1 (10 fl oz) | 568.3 (20 fl oz) |\n\nUS imperial: 1 UK pint = 20 fl oz; US pint = 16 fl oz. UK fl oz = 28.4 mL; US fl oz = 29.57 mL. **A \"pint\" in a US recipe ≠ a \"pint\" in a UK recipe.**\n\n**Weight vs volume ounce (do NOT confuse)**\n\n1 weight ounce (oz) = 28.35 grams.\n1 fluid ounce (fl oz) = 29.57 mL (US) or 28.41 mL (UK).\n\nFor WATER specifically, they happen to be close (1 fl oz water ≈ 1 weight oz water at 4°C). For other ingredients, weight and volume diverge significantly. Always check whether your recipe specifies \"oz\" by weight or \"fl oz\" by volume.\n\n**Common cooking scenarios**\n\n- \"8 fl oz milk\" → 1 cup = 240 mL (close enough)\n- \"12 fl oz beer\" → 1.5 cups (one standard beer bottle)\n- \"16 fl oz can of broth\" → 2 cups (one US standard can)\n- \"32 fl oz quart of stock\" → 4 cups\n- \"1/2 gallon (64 fl oz) milk\" → 8 cups\n\n**Why this conversion shows up so often**\n\nUS recipe books and supermarket packaging frequently mix cup and fl oz units in the same recipe (\"1 cup milk + 4 fl oz cream\"). They are the same measurement system (volume), so swapping is mechanical: 1 cup = 8 fl oz. Just remember to halve, double, or convert directly.\n\n**Cross-reference:** see /pages/how-to-convert/tablespoons-to-cups for tbsp ↔ cup + /pages/how-to-convert/ml-to-cups for direct mL conversion + /pages/how-to-convert/milliliters-to-tablespoons for mL ↔ tbsp.","ranges":[{"condition":"US fluid ounce to cup","duration":"< 5 seconds","note":"fl oz ÷ 8 = cups"},{"condition":"UK fluid ounce (rare)","duration":"10 seconds","note":"UK fl oz × 28.41 mL, then ÷ 236.6 mL for US cup"},{"condition":"Pint to cups","duration":"5 seconds","note":"1 US pint = 16 fl oz = 2 US cups"}],"variables":[{"name":"US vs UK","effect":"1 US pint = 16 fl oz (473 mL). 1 UK pint = 20 fl oz (568 mL). 17% difference."},{"name":"Weight oz vs fluid oz","effect":"Weight: 28.35 g. Fluid (US): 29.57 mL. Roughly equal for water; very different for oils/honey/syrup."},{"name":"Legal vs customary cup","effect":"US customary = 236.6 mL (8 × 29.57). US legal (FDA labels) = 240 mL (8 × 30). 1.4% difference."}],"sources":[{"label":"NIST — Customary System units","url":"https://www.nist.gov/pml/owm/metric-cooking-resources","note":"Authoritative US measurement definitions","tier":1},{"label":"FDA — Food Labeling Reference Amounts","url":"https://www.fda.gov/food/food-labeling-nutrition/food-labeling-guide","note":"US legal cup definition for nutrition labels","tier":1},{"label":"King Arthur Baking — measurement basics","url":"https://www.kingarthurbaking.com/learn/guides/converting-volume-to-weight","note":"Practical conversion guide","tier":2},{"label":"BIPM (UK + International) — Imperial pint","note":"Historical UK fluid ounce + pint definitions","tier":1}],"faq":[{"question":"Why is the US gallon different from the UK gallon?","answer":"US gallon = 128 US fl oz = 3.785 L. UK (imperial) gallon = 160 UK fl oz = 4.546 L. The UK gallon is 20% LARGER than the US gallon. The US gallon was set to the older \"Queen Anne wine gallon\" (231 cubic inches); the UK redefined its gallon in 1824 to 10 lb of water at specific conditions. If you use British recipes, \"1 gallon\" of liquid is much more than a US gallon."},{"question":"How do I know if a recipe means weight oz or fluid oz?","answer":"Three checks: (1) Ingredient type — water, milk, oil, juice = almost always fluid oz (volume). Meat, cheese, butter, chocolate = almost always weight oz. (2) Whether the recipe also lists grams or mL — if it lists both, \"oz\" matches the unit type given. (3) Recipe origin — US/UK home cooking mixes both freely; pastry-quality recipes (King Arthur, ATK) typically specify \"fl oz\" for liquids and just \"oz\" for weight."},{"question":"Are cup measurements consistent across countries?","answer":"No. US cup = 236.6 mL (customary) or 240 mL (legal). Metric cup (Australia, NZ, parts of UK/EU) = 250 mL. Imperial cup (rare; historical UK) = 284 mL. Japanese cup = 200 mL. When converting recipes from a different country, always identify which cup standard the recipe uses; the 5-20% variance affects most recipes meaningfully."}],"keywords":["fluid ounces to cups","fl oz to cups","cup ounce conversion","US imperial measurement"],"category":"cooking","date_published":"2026-05-21","date_modified":"2026-05-21","license":"CC-BY-4.0","attribution":"https://askedwell.com"}