How many ounces are in a cup?

A US cup holds 8 fluid ounces, which is about 237 mL.

How many ounces are in a gallon?

A US gallon holds 128 fluid ounces, equal to 8 pints or 4 quarts.

How many ounces are in a pint?

A US pint is 16 fluid ounces; a UK imperial pint is 20 fluid ounces.

Are US and UK ounces the same?

No. A US fluid ounce is 29.57 mL and a UK imperial fluid ounce is 28.41 mL — close but not identical.

How Many Ounces in a Cup, Pint, and Gallon?

Published 6/2/2026 · 3 min read · Everyday calculators

Marco Bianchi — Home, DIY & motoring writer at Allin

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In short

In the US customary system, 1 cup holds 8 fluid ounces, 1 pint holds 16 fluid ounces (2 cups), 1 quart holds 32 fluid ounces (2 pints), and 1 gallon holds 128 fluid ounces (4 quarts). Each step doubles the one before, except cup to gallon. In milliliters, a US fluid ounce is about 29.57 mL, so a cup is roughly 237 mL and a gallon about 3.79 liters. Be careful: the UK (imperial) fluid ounce is 28.41 mL, and an imperial pint is 20 ounces, not 16.

A US cup holds 8 fluid ounces, a pint 16, a quart 32, and a gallon 128. See the full chart with milliliter equivalents and why US and UK ounces are not the same.

The US volume ladder

US liquid measures build on one another in a neat chain. There are 8 fluid ounces in a cup, 2 cups in a pint, 2 pints in a quart, and 4 quarts in a gallon. Multiply through and a pint is 16 ounces, a quart is 32 ounces, and a gallon is 128 ounces. Remembering "8, 16, 32, 128" covers almost every kitchen conversion.

In milliliters, a US fluid ounce is 29.5735 mL. So a cup is about 237 mL, a pint about 473 mL, a quart about 946 mL, and a gallon about 3,785 mL, or 3.79 liters. These round numbers — roughly a quarter liter per cup and just under 4 liters per gallon — are useful when a recipe mixes units.

US versus UK ounces

The word "ounce" hides two different volumes. A US fluid ounce is 29.57 mL, while a UK (imperial) fluid ounce is 28.41 mL — slightly smaller. That gap grows across larger measures: an imperial pint is 20 fluid ounces and about 568 mL, whereas a US pint is 16 fluid ounces and about 473 mL.

The gallon differs even more. A US gallon is 3.785 liters, while an imperial gallon is 4.546 liters — about 20% larger. So a UK recipe or fuel figure quoted in gallons is not the same quantity as a US one. Always confirm which system a source uses before converting, especially for large volumes.

Handy shortcuts to memorize

A few anchors make mental conversion fast. Two tablespoons equal 1 fluid ounce, so a cup is also 16 tablespoons. Four cups make a quart, and four quarts make a gallon — the classic "gallon man" diagram nests cups inside pints inside quarts inside a gallon.

For metric cooks, remember a cup is close to a quarter liter and a quart is close to a liter (946 mL). A gallon is just under 4 liters. These approximations are fine for most cooking, but for baking, where ratios matter, use a converter that gives the exact milliliter value rather than the rounded one.

Volume converterConvert between mL, L, m³, gal, pt and more. Free volume converter, instant and accurate.Try the tool →

Frequently asked questions

How many ounces are in a cup?: A US cup holds 8 fluid ounces, which is about 237 mL.
How many ounces are in a gallon?: A US gallon holds 128 fluid ounces, equal to 8 pints or 4 quarts.
How many ounces are in a pint?: A US pint is 16 fluid ounces; a UK imperial pint is 20 fluid ounces.
Are US and UK ounces the same?: No. A US fluid ounce is 29.57 mL and a UK imperial fluid ounce is 28.41 mL — close but not identical.

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