A gallon of water is significantly larger and heavier than a quart of water. You can picture a quart as a glass 4.11 in (10.4 cm) wide and 5.13 in (13 cm) tall, while a gallon is a glass 6.52 in (16.6 cm) wide and 8.15 in (20.7 cm) tall.

Biggest vs smallest
1.59× the size
1 gal of water vs 1 qt of water
Typical adult or standard sizes; real ones vary.