One gallon of water is equal to 16 cups. One gallon is also equal to 8 pints or 4 quarts. One cup of liquid is equal to 2 pints.
An easy breakdown of liquid conversions is, 2 cups equal 1 pint, 2 pints equal 1 quart and 4 quarts equal 1 gallon. One cup of liquid is equal to 8 fluid ounces, so 1 gallon is equal to 128 fluid ounces. Additionally, 1 quart equals 1/4 of a gallon. The cup measure is convenient for smaller amounts of liquid and the gallon is a convenient unit of measurement for larger amounts of liquid.