How Many Cups in a Gallon?
There are exactly 16 cups in one US gallon.
How to Convert Gallons to Cups
To convert gallons to cups, multiply by 16.
For example: 5 gallons × 16 = 80 cups.
Why This Number Matters
Batch cooking, iced tea, brines and punch recipes scale between cups and gallons. The number also settles the common daily-water-intake question, since eight 8-ounce glasses is half a gallon.
The "eight glasses of water a day" advice is eight 8-ounce cups, which is 64 fluid ounces — half a gallon, not a whole one.
What People Get Wrong
A UK imperial gallon holds 19.2 US cups, because the imperial gallon is about 20 percent larger. British recipes using gallons need converting before the cup count applies.
Gallons to Cups Conversion Table
| Gallons (gal) | Cups (cup) |
|---|---|
| 1 | 16 |
| 2 | 32 |
| 3 | 48 |
| 4 | 64 |
| 5 | 80 |
| 6 | 96 |
| 7 | 112 |
| 8 | 128 |
| 9 | 144 |
| 10 | 160 |
| 11 | 176 |
| 12 | 192 |
| 13 | 208 |
| 14 | 224 |
| 15 | 240 |
| 16 | 256 |
| 17 | 272 |
| 18 | 288 |
| 19 | 304 |
| 20 | 320 |
| 25 | 400 |
| 30 | 480 |
| 40 | 640 |
| 50 | 800 |
| 75 | 1,200 |
| 100 | 1,600 |
| 250 | 4,000 |
| 500 | 8,000 |
| 1,000 | 16,000 |
About These Units
The gallon
A US liquid gallon is exactly 3.785411784 liters, made up of 4 quarts or 128 fluid ounces. The UK imperial gallon is a different unit of 4.546 liters, about 20 percent larger.
The cup
A US customary cup is 8 fluid ounces, or exactly 236.5882365 milliliters. Nutrition labels use a separate "legal cup" of exactly 240 milliliters, and a metric cup is 250 milliliters.
Definitions follow NIST Handbook 44, Appendix C. See how we calculate for the exact values and rounding rules.
Frequently Asked Questions
How many cups in half a gallon?
Half a gallon is 8 cups, or 64 fluid ounces.
How many ounces in a gallon?
A US gallon is 128 fluid ounces.
How many quarts in a gallon?
4 quarts, each of which is 4 cups.
How many liters in a gallon?
A US gallon is exactly 3.785411784 liters.