Cups to Fluid Ounces Converter (Cups ⇄ fl oz)

Convert US cups to fluid ounces instantly for cooking, baking, and beverages. 1 cup = 8 fluid ounces (fl oz), 1/2 cup = 4 fl oz, 1/4 cup = 2 fl oz. This converter measures volume, not weight. Perfect for recipes and drink measurements.

Cups ⇄ Fluid Ounces Calculator

Convert US cup to US fluid ounce (fl oz) and back. Perfect for fast cooking & baking conversions.

Key fact: 1 cup = 8 fl oz (this measures volume, not weight)

How many ounces in 1 cup?

1 cup = 8 fluid ounces (fl oz)

This is a volume measurement. The standard US cup holds exactly 8 fluid ounces of liquid.

Complete Cups to Fluid Ounces Conversion Chart

Quick reference table for converting US cups to fluid ounces. All measurements use the standard US cup (8 fl oz).

Fractional Cup Measurements

Cups Fluid Ounces (fl oz) Tablespoons
1/8 cup 1 fl oz 2 tbsp
1/4 cup 2 fl oz 4 tbsp
1/3 cup 2.67 fl oz 5 tbsp + 1 tsp
1/2 cup 4 fl oz 8 tbsp
2/3 cup 5.33 fl oz 10 tbsp + 2 tsp
3/4 cup 6 fl oz 12 tbsp
1 cup 8 fl oz 16 tbsp

Whole Cup Measurements

Cups Fluid Ounces (fl oz) Milliliters (mL)
1 cup 8 fl oz 237 mL
1.5 cups 12 fl oz 355 mL
2 cups 16 fl oz 473 mL (1 pint)
3 cups 24 fl oz 710 mL
4 cups 32 fl oz 946 mL (1 quart)
8 cups 64 fl oz 1,893 mL (1/2 gallon)
16 cups 128 fl oz 3,785 mL (1 gallon)

Fluid Ounces to Cups

Fluid Ounces (fl oz) Cups Common Use
1 fl oz 0.125 cups (1/8) Shot glass
2 fl oz 0.25 cups (1/4) Small juice glass
4 fl oz 0.5 cups (1/2) Small coffee cup
6 fl oz 0.75 cups (3/4) Tea cup
8 fl oz 1 cup Standard cup
12 fl oz 1.5 cups Soda can
16 fl oz 2 cups 1 pint
32 fl oz 4 cups 1 quart

Fluid Ounces vs Ounces: Understanding the Difference

This is one of the most common sources of confusion in cooking! Fluid ounces and ounces are NOT the same thing.

⚠️ Critical Difference

Fluid Ounces (fl oz): Measure VOLUME (space occupied)
Ounces (oz): Measure WEIGHT (mass)

Real-World Examples

Liquid Volume Weight
Water 8 fl oz ~8.3 oz weight
Milk 8 fl oz ~8.6 oz weight
Honey 8 fl oz ~12 oz weight
Vegetable oil 8 fl oz ~7.7 oz weight
Maple syrup 8 fl oz ~11 oz weight

Key takeaway: 8 fluid ounces of ANY liquid always takes up the same amount of space (1 cup), but different liquids weigh different amounts. Water is roughly equal (8 fl oz ≈ 8 oz weight), but denser liquids like honey weigh more, and lighter liquids like oil weigh less.

✓ Remember: When a recipe says "8 ounces," check the context:

  • For liquids → usually means 8 fluid ounces (1 cup)
  • For dry ingredients → usually means 8 ounces by weight
  • Look for "fl oz" or "fluid ounces" to be sure

How to Convert Cups to Fluid Ounces

✓ The Formula

fl oz = cups × 8

To go the other way: cups = fl oz ÷ 8

Step-by-Step Examples

Example 1: Convert 3 cups to fluid ounces

  1. Start with the amount: 3 cups
  2. Multiply by 8: 3 × 8 = 24 fl oz
  3. Result: 3 cups = 24 fl oz

Example 2: Convert 1/2 cup to fluid ounces

  1. Start with the fraction: 1/2 cup = 0.5 cups
  2. Multiply by 8: 0.5 × 8 = 4 fl oz
  3. Result: 1/2 cup = 4 fl oz

Example 3: Convert 12 fl oz to cups

  1. Start with fluid ounces: 12 fl oz
  2. Divide by 8: 12 ÷ 8 = 1.5 cups
  3. Result: 12 fl oz = 1.5 cups (or 1 1/2 cups)

Practical Tips for Measuring Liquids

📏 Use Liquid Measuring Cups

Liquid measuring cups (usually glass or clear plastic with a spout) are designed to be filled while sitting on the counter. Check at eye level for accuracy.

👁️ Read at Eye Level

Place the measuring cup on a flat surface and bend down to read the measurement at eye level. Reading from above causes errors.

💧 Read the Meniscus

The liquid surface curves slightly. Read the measurement at the bottom of the curve (the meniscus), not the top edges where liquid climbs the container.

⚖️ Weight for Accuracy

For the most precise baking, use a kitchen scale and measure liquids by weight in grams. This eliminates all measurement errors.

Frequently Asked Questions

How many fluid ounces in 1 cup?

1 US cup = 8 fluid ounces (fl oz). This is a standard volume measurement used throughout American cooking and baking. The relationship is exact: 1 cup always equals exactly 8 fl oz.

How many ounces in 1/2 cup?

1/2 cup = 4 fluid ounces. This is exactly half of a standard cup. Remember this is fluid ounces (volume), not weight ounces.

How many ounces in 1/4 cup?

1/4 cup = 2 fluid ounces. This is one quarter of a standard US cup, or 4 tablespoons.

What's the difference between fluid ounces and ounces?

Fluid ounces (fl oz) measure volume (the space something occupies), while ounces (oz) measure weight (how heavy something is). 8 fl oz of water weighs about 8 oz, but 8 fl oz of honey weighs about 12 oz because honey is denser. Always check whether a recipe calls for fluid ounces or weight ounces!

How many cups is 16 fl oz?

16 fluid ounces = 2 cups. This is also equal to 1 pint. Divide any number of fluid ounces by 8 to get cups: 16 ÷ 8 = 2 cups.

How many cups is 12 fl oz?

12 fluid ounces = 1.5 cups (or 1 1/2 cups). This is a common beverage can size. Formula: 12 ÷ 8 = 1.5 cups.

How many cups is 32 fl oz?

32 fluid ounces = 4 cups. This is also equal to 1 quart or 946 mL. Formula: 32 ÷ 8 = 4 cups.

Is 8 oz the same as 1 cup?

Yes, 8 fluid ounces equals 1 cup. However, be careful: if the recipe just says "8 oz" without specifying "fluid ounces," check the context. For liquids it usually means 8 fl oz (1 cup), but for dry ingredients it might mean 8 ounces by weight (which varies by ingredient).

Can I use a regular drinking glass to measure cups?

No! Regular drinking glasses vary widely in size. A standard measuring cup holds exactly 8 fluid ounces. Always use proper measuring cups or a kitchen scale for accurate results in cooking and baking.

Common Beverage Sizes in Cups and Fluid Ounces

Beverage Fluid Ounces Cups
Shot 1.5 fl oz ~0.19 cups
Coffee cup (small) 6 fl oz 0.75 cups (3/4)
Coffee mug (standard) 8-12 fl oz 1-1.5 cups
Soda can 12 fl oz 1.5 cups
Water bottle (standard) 16.9 fl oz ~2.1 cups
Pint glass 16 fl oz 2 cups
Large coffee (Starbucks Venti) 20 fl oz 2.5 cups
Wine bottle 25.4 fl oz ~3.2 cups

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