U.S. customary units: how many in one?
15 facts, all exact by definition (NIST Handbook 44). Ounces here are avoirdupois weight ounces and U.S. fluid ounces of volume, which are different units. The mile and the gallon each appear twice, in two different units. The U.S. ton is the short ton; the British long ton is 2,240 pounds.
Recipes, road signs, lumber and gas pumps in the United States all use these units. Knowing how they nest inside each other lets you double a recipe, measure a room or read a map without reaching for a calculator.
Learn each family as one chain, since the units nest: teaspoon, tablespoon, fluid ounce, cup, pint, quart, gallon (3, 2, 8, 2, 2, 4). Draw it once as nesting boxes, a big G with four Qs inside, two Ps in each Q and two Cs in each P: picture plus words. Then length (12, 3, 5,280), weight (16, 2,000) and area (43,560, 640). Say each fact as a sentence, "one gallon is four quarts," and quiz yourself both ways.
Encode make it vivid → Space bring it back on day 1, 3, 7, 21 → Retrieve pull it from your head. From the infographic Remember It on Purpose.
U.S. customary units: how many in one?
| One... | equals | of these | Kind |
|---|---|---|---|
| foot | 12 | inches | Length |
| yard | 3 | feet | Length |
| mile | 5,280 | feet | Length |
| mile | 1,760 | yards | Length |
| tablespoon | 3 | teaspoons | Kitchen volume |
| fluid ounce | 2 | tablespoons | Kitchen volume |
| cup | 8 | fluid ounces | Kitchen volume |
| pint | 2 | cups | Kitchen volume |
| quart | 2 | pints | Kitchen volume |
| gallon | 4 | quarts | Kitchen volume |
| gallon | 231 | cubic inches | Kitchen volume |
| pound | 16 | ounces | Weight |
| short ton | 2,000 | pounds | Weight |
| acre | 43,560 | square feet | Area |
| square mile | 640 | acres | Area |
Learn each family as one chain, since the units nest: teaspoon, tablespoon, fluid ounce, cup, pint, quart, gallon (3, 2, 8, 2, 2, 4). Draw it once as nesting boxes, a big G with four Qs inside, two Ps in each Q and two Cs in each P: picture plus words. Then length (12, 3, 5,280), weight (16, 2,000) and area (43,560, 640). Say each fact as a sentence, "one gallon is four quarts," and quiz yourself both ways. · teddyrookbook.com/memory/challenges/us-customary-units/
Sources
Checked October 30, 2026. Progress is kept on this device only (per learner). More lists: all memory challenges · memory games.