How many ounces in a glass?

1 glass of water = 8 fl oz

by custom, not by definition · 1 cup · 237 mL · wine pour 5 fl oz · beer 12 fl oz · pint glass 16 fl oz

Converter

Common amounts in fl oz

8 fl oz = 1 cup

Fluid ounces
8 fl oz
Cups
1
Tablespoons
16
Teaspoons
48
Milliliters
237 mL
Measure with
1 cup
Spoons only
16 Tbsp

Full guide: 8 fl oz

Scale:
Other cup standards

US cups: 1 · nutrition-label cups (240 mL): 0.986 · metric cups (250 mL): 0.946 · UK fluid ounces: 8.33

US customary cup = 236.6 mL

A glass is not a unit of measure, so the answer depends on the glass. When advice or a recipe counts glasses of water, it means 8 US fluid ounces: one measuring cup, about 237 mL. Eight of those glasses add up to 64 fl oz, which is a half gallon or about 1.89 liters.

The glasses in your cupboard can hold less or more than that. To find out, fill one from a measuring cup and count. For drinks, the US National Institute on Alcohol Abuse and Alcoholism describes a standard drink as 12 fl oz of regular beer, 5 fl oz of table wine or a 1.5 fl oz shot of distilled spirits.

A US pint glass filled to the rim holds 16 fl oz, or 2 cups. A British pint glass holds 20 imperial fl oz, about 19.2 US fl oz. More on each size at cups in a pint, 5 oz to cups and 12 oz to cups.

Common glasses in US fluid ounces, cups and mL
GlassUS fl ozCupsmL
Glass of water, as in "8 glasses a day"81237
Standard glass of wine55/8148
Standard beer (can or bottle)121 1/2355
US pint glass, full162473
UK pint glass (20 imperial fl oz)19.22.4568
Shot glass1.53 Tbsp44
Glasses of water (8 fl oz each) in ounces, cups and liters
GlassesUS fl ozCupsLiters
1810.24
21620.47
32430.71
43240.95
64861.42
86481.89
1080102.37
1296122.84
16128163.79
How many 8 fl oz glasses are in a bottle
ContainerUS fl oz8 fl oz glasses
16.9 fl oz bottle (500 mL)16.92.11
1 liter33.84.23
2 liters67.68.45
Half gallon648
1 gallon12816

Wine, beer and shot sizes: NIAAA, "What Is a Standard Drink?" (consulted 2026-11-10).

How many 8 oz glasses are in 2 liters?

About 8.45 glasses. Two liters is 67.6 US fl oz, and each glass is 8. One liter fills about 4.23 glasses and a US gallon exactly 16. See cups in a liter for other bottle sizes.

How many mL is a glass of water?

An 8 fl oz glass is 236.6 mL, usually rounded to 237 mL. US nutrition labels round a cup to 240 mL, and countries that cook with metric cups use 250 mL, so a "glass" in a metric recipe is slightly larger.

Questions

How many ounces in a glass of water?

8 US fl oz when "a glass" is used as a measure, the same as 1 cup. Real drinking glasses vary.

How many ounces in a glass of beer?

A standard US beer is 12 fl oz (NIAAA). A US pint glass holds 16 fl oz.

How many ounces in a glass of wine?

A standard pour is 5 fl oz (NIAAA), a little over 1/2 cup.

How many ounces is 8 glasses of water?

64 fl oz, which is 8 cups, a half gallon or about 1.89 liters.

By Alton Vieira · Updated . Sources: US customary units: NIST Handbook 44. How we calculate.