Convert US cups to fluid ounces instantly. Free calculator, full reference table, fraction guide, and cooking examples — accurate, no sign-up required.
Quick Answer: 1 US cup = 8 fluid ounces. To convert cups to oz, multiply by 8. Common values: ¼ cup = 2 fl oz · ½ cup = 4 fl oz · ¾ cup = 6 fl oz · 1 cup = 8 fl oz · 2 cups = 16 fl oz · 4 cups = 32 fl oz · 8 cups = 64 fl oz · 16 cups = 128 fl oz (1 gallon).
Formula: fl oz = cups × 8 (US customary cup)
Fluid Ounces = US Cups × 8
US Cups = Fluid Ounces ÷ 8
One US cup is defined as exactly 8 US fluid ounces — a fixed relationship in the US customary measurement system. Because the multiplier is a whole number, cups to oz is one of the easiest kitchen conversions to do mentally: double the cups to get the ounce count in units of 16, or just multiply any cup value by 8. All results on this page use the US customary cup (236.6 ml / 8 fl oz), which is the standard in American cookbooks and recipe websites.
This cups to oz conversion chart covers the full range of values — from fractional cups used in everyday cooking to large multi-cup quantities for batch recipes and catering.
| US Cups | Fluid Ounces (fl oz) | Fraction | Common Reference |
|---|---|---|---|
| ⅛ cup | 1 fl oz | ⅛ | 2 tablespoons |
| ¼ cup | 2 fl oz | ¼ | 4 tablespoons |
| ⅓ cup | 2.667 fl oz | ⅓ | 5 tbsp + 1 tsp |
| ½ cup | 4 fl oz | ½ | 8 tablespoons / half cup |
| ⅔ cup | 5.333 fl oz | ⅔ | 10 tbsp + 2 tsp |
| ¾ cup | 6 fl oz | ¾ | 12 tablespoons |
| 1 cup | 8 fl oz | 1 | standard US cup |
| 1¼ cups | 10 fl oz | 1¼ | — |
| 1⅓ cups | 10.667 fl oz | 1⅓ | — |
| 1½ cups | 12 fl oz | 1½ | standard soda can |
| 1¾ cups | 14 fl oz | 1¾ | — |
| 2 cups | 16 fl oz | 2 | 1 pint |
| 2½ cups | 20 fl oz | 2½ | large vending bottle |
| 3 cups | 24 fl oz | 3 | sport bottle |
| 3½ cups | 28 fl oz | 3½ | — |
| 4 cups | 32 fl oz | 4 | 1 quart |
| 5 cups | 40 fl oz | 5 | — |
| 6 cups | 48 fl oz | 6 | — |
| 7 cups | 56 fl oz | 7 | — |
| 8 cups | 64 fl oz | 8 | ½ gallon |
| 9 cups | 72 fl oz | 9 | — |
| 10 cups | 80 fl oz | 10 | — |
| 12 cups | 96 fl oz | 12 | ¾ gallon |
| 16 cups | 128 fl oz | 16 | 1 gallon |
| 20 cups | 160 fl oz | 20 | 1¼ gallons |
| 24 cups | 192 fl oz | 24 | 1½ gallons |
| 32 cups | 256 fl oz | 32 | 2 gallons |
Recipes often call for values like 1¼ cups or 2⅔ cups. This table covers every fractional and decimal cup measurement you are likely to encounter, with the exact fluid ounce equivalent for each.
| Cups (fraction) | Cups (decimal) | Fluid Ounces | Tablespoons |
|---|---|---|---|
| ⅛ cup | 0.125 | 1 fl oz | 2 tbsp |
| ¼ cup | 0.25 | 2 fl oz | 4 tbsp |
| ⅓ cup | 0.333 | 2.667 fl oz | 5 tbsp + 1 tsp |
| ½ cup | 0.5 | 4 fl oz | 8 tbsp |
| ⅔ cup | 0.667 | 5.333 fl oz | 10 tbsp + 2 tsp |
| ¾ cup | 0.75 | 6 fl oz | 12 tbsp |
| 1 cup | 1.0 | 8 fl oz | 16 tbsp |
| 1¼ cups | 1.25 | 10 fl oz | 20 tbsp |
| 1⅓ cups | 1.333 | 10.667 fl oz | 21 tbsp + 1 tsp |
| 1½ cups | 1.5 | 12 fl oz | 24 tbsp |
| 1⅔ cups | 1.667 | 13.333 fl oz | 26 tbsp + 2 tsp |
| 1¾ cups | 1.75 | 14 fl oz | 28 tbsp |
| 2 cups | 2.0 | 16 fl oz | 32 tbsp |
| 2¼ cups | 2.25 | 18 fl oz | 36 tbsp |
| 2⅓ cups | 2.333 | 18.667 fl oz | 37 tbsp + 1 tsp |
| 2½ cups | 2.5 | 20 fl oz | 40 tbsp |
| 2⅔ cups | 2.667 | 21.333 fl oz | 42 tbsp + 2 tsp |
| 2¾ cups | 2.75 | 22 fl oz | 44 tbsp |
| 3 cups | 3.0 | 24 fl oz | 48 tbsp |
| 3¼ cups | 3.25 | 26 fl oz | 52 tbsp |
| 3½ cups | 3.5 | 28 fl oz | 56 tbsp |
| 3¾ cups | 3.75 | 30 fl oz | 60 tbsp |
| 4 cups | 4.0 | 32 fl oz | 64 tbsp |
| 4½ cups | 4.5 | 36 fl oz | 72 tbsp |
| 5 cups | 5.0 | 40 fl oz | 80 tbsp |
Mental math shortcut: For any cup value, multiply by 8 to get fl oz. For fractions: ¼ cup = 2 fl oz, ½ cup = 4 fl oz, ¾ cup = 6 fl oz. Each additional ¼ cup adds exactly 2 fl oz. So 1¾ cups = 8 + 6 = 14 fl oz, and 2¾ cups = 16 + 6 = 22 fl oz.
The most frequent source of confusion in cups to oz conversions is the difference between fluid ounces (volume) and weight ounces (mass). These are two completely different units that happen to share a name.
When a recipe says "1 cup of milk," it means 8 fl oz of milk by volume — and this page gives you the correct fl oz answer. When a recipe says "1 cup of all-purpose flour," it also means 8 fl oz of flour by volume, but that volume of flour weighs only about 4.25 oz (120 g) by mass — very different from 8 oz by weight.
| Measurement Type | Unit | What It Measures | 1 Cup Equivalent |
|---|---|---|---|
| Liquid volume | fl oz (fluid ounce) | Volume | 1 cup = 8 fl oz |
| Dry weight | oz (weight ounce) | Mass | varies by ingredient |
The table below shows how much common dry ingredients actually weigh when measured as 1 cup of volume. This is the "dry oz per cup" question many bakers ask:
| Ingredient | 1 Cup Volume | Weight in oz | Weight in grams |
|---|---|---|---|
| All-purpose flour | 8 fl oz | ~4.25 oz | ~120 g |
| Bread flour | 8 fl oz | ~4.8 oz | ~136 g |
| Granulated sugar | 8 fl oz | ~7.05 oz | ~200 g |
| Brown sugar (packed) | 8 fl oz | ~7.75 oz | ~220 g |
| Powdered sugar | 8 fl oz | ~4.0 oz | ~113 g |
| Cocoa powder | 8 fl oz | ~3.5 oz | ~100 g |
| Rolled oats | 8 fl oz | ~3.17 oz | ~90 g |
| Rice (uncooked) | 8 fl oz | ~6.5 oz | ~185 g |
| Butter (melted) | 8 fl oz | ~7.7 oz | ~218 g |
| Honey | 8 fl oz | ~12 oz | ~340 g |
Rule of thumb: Use fluid ounces for liquid ingredients — water, milk, oil, broth, juice. Use a kitchen scale in grams or weight ounces for dry ingredients — flour, sugar, cocoa, oats. The cups to oz conversion on this page is accurate for all liquid measurements and for volume-based dry measurements.
A "cup" means different volumes in different countries. If you are converting cups to oz from a non-US recipe, the cup size matters significantly.
| Cup Type | Volume (ml) | Fluid Ounces | Used In |
|---|---|---|---|
| US Customary Cup | 236.6 ml | 8 fl oz (exact) | US recipes, cookbooks |
| US Legal Cup | 240 ml | ~8.115 fl oz | US Nutrition Facts labels |
| Metric Cup | 250 ml | ~8.454 fl oz | Australia, Canada, NZ, South Africa |
| Imperial Cup | 284.1 ml | ~9.608 fl oz | older UK recipes |
| Japanese Cup | 200 ml | ~6.763 fl oz | Japan |
This calculator uses the US customary cup (8 fl oz / 236.6 ml) — the standard for American recipes. For Australian or Canadian recipes using a 250 ml cup, 1 cup equals approximately 8.45 fl oz rather than 8. The difference is about 5.6%, which is negligible for most recipes but relevant for precise baking.
Understanding where cups sit in the US liquid measurement system makes multi-step conversions straightforward — for example, converting 3 cups directly to quarts or gallons without an intermediate step.
| Unit | fl oz | Cups | Pints | Quarts | Gallons |
|---|---|---|---|---|---|
| 1 tablespoon | 0.5 | 0.0625 | — | — | — |
| 1 fl oz | 1 | 0.125 | — | — | — |
| 1 cup | 8 | 1 | 0.5 | 0.25 | 0.0625 |
| 1 pint | 16 | 2 | 1 | 0.5 | 0.125 |
| 1 quart | 32 | 4 | 2 | 1 | 0.25 |
| ½ gallon | 64 | 8 | 4 | 2 | 0.5 |
| 1 gallon | 128 | 16 | 8 | 4 | 1 |
One cup is half a pint and one-quarter of a quart. If you need to go the other direction — converting fluid ounces back into cups — use the oz to cups converter. For large-volume conversions involving gallons, the oz to gallon converter on the homepage covers those calculations.
These are the most common real-world scenarios where a cups to oz conversion is needed — either to match a container label, scale a recipe, or measure without a liquid measuring cup.
| Recipe / Scenario | Cups | Fluid Ounces | Notes |
|---|---|---|---|
| Cake batter (milk) | 1 cup | 8 fl oz | standard measuring cup |
| Pancake batter (milk) | 1½ cups | 12 fl oz | soda can equivalent |
| Soup broth (single serve) | 2 cups | 16 fl oz | 1 pint / standard bottle |
| Smoothie (blender) | 1–2 cups | 8–16 fl oz | depends on recipe |
| Pasta cooking water | 8 cups | 64 fl oz | ½ gallon / large pot |
| Chicken broth (soup pot) | 4 cups | 32 fl oz | 1 standard carton |
| Lemonade (pitcher) | 6 cups | 48 fl oz | standard pitcher size |
| Vinegar brine (pickling) | 2 cups | 16 fl oz | pint jar |
| Cream (whipping) | 2 cups | 16 fl oz | standard pint carton |
| Maple syrup (batch) | ½ cup | 4 fl oz | 8 tablespoons |
| Olive oil (salad dressing) | ¼ cup | 2 fl oz | 4 tablespoons |
| Punch (party bowl) | 16 cups | 128 fl oz | 1 gallon |
Scaling tip: When doubling or halving a recipe, convert cups to fl oz first, then scale. It is easier to halve "16 fl oz" than to halve "2 cups" when you only have a liquid measuring cup graduated in ounces. The reverse is equally useful — if a carton says "32 fl oz," you already know that is 4 cups without measuring.
These are the errors that appear most often when people convert cups to oz in a kitchen setting:
❌ Multiplying by 16 instead of 8
A common mix-up: 16 oz is the number of fluid ounces in a pint, not a cup. One cup = 8 fl oz, not 16. Multiplying by 16 would give you pints converted to fl oz, not cups to fl oz. Always use 8 as the multiplier for cups.
❌ Treating "8 oz" on a package as 1 cup of a dry ingredient
An 8 oz bag of shredded cheese is 8 oz by weight — not 1 cup by volume. 1 cup of shredded cheese typically weighs about 4 oz, so an 8 oz bag contains roughly 2 cups. Weight ounces and fluid ounces are different measurements entirely.
❌ Using a metric cup for a US recipe
Australian and Canadian measuring cups hold 250 ml (≈ 8.45 fl oz), about 5.6% more than a US cup (236.6 ml / 8 fl oz). For most cooking this difference is harmless, but when baking bread or pastry — where hydration ratios matter — always confirm which cup standard the recipe uses.
❌ Forgetting that ⅓ cup does not convert to a round number
⅓ cup = 2.667 fl oz and ⅔ cup = 5.333 fl oz — these are repeating decimals. If you need an exact volume, use tablespoons: ⅓ cup = 5 tablespoons + 1 teaspoon, and ⅔ cup = 10 tablespoons + 2 teaspoons. Rounding to 2.7 or 5.3 fl oz introduces a small but real error.
US cup and fluid ounce definitions are governed by standards maintained by the National Institute of Standards and Technology (NIST). The distinction between fluid ounces and weight ounces is covered by Encyclopædia Britannica's entry on the ounce. For everyday hydration context using cups and ounces, see the USGS Water Science School.
All the liquid volume converters you need, in one place.
Reverse converter — go from fluid ounces back to US cups. 8 fl oz = 1 cup.
Convert fluid ounces to US gallons — useful when scaling cups up to gallon quantities.
Convert fluid ounces to pints — 2 cups = 1 pint, so these two are closely related.
Convert fluid ounces to quarts — 4 cups = 1 quart, the next step up from cups.
Convert fluid ounces to milliliters for metric recipe scaling — 1 fl oz = 29.5735 ml.
Convert fluid ounces to liters when working with metric measurements or international recipes.
Convert gallons to fluid ounces — helpful when breaking a gallon-batch recipe into cup measurements.