How much does a gallon of water weigh

General
1

how much does a gallon of water weigh

2

How much does a gallon of water weigh?

Answer:
The weight of a gallon of water depends on the temperature, as water density changes with temperature. However, under standard conditions of temperature and pressure, we can provide a straightforward answer.

Weight of a US Gallon of Water

  1. Standard Conditions: At a temperature of 4 degrees Celsius (39.2 degrees Fahrenheit), where water is densest:

    • A US gallon (which equals 3.78541 liters) weighs approximately 8.34 pounds (lbs) or about 3.785 kilograms (kg).

  2. Temperature Variance: The weight slightly varies with temperature:

    • Hot Water: Water expands when heated, so a gallon of hot water weighs slightly less than 8.34 pounds.
    • Cold Water: Water contracts when cooled, so a gallon of cold water can weigh a bit more than 8.34 pounds.

Weight of an Imperial Gallon of Water

An Imperial gallon, used primarily in the United Kingdom, is larger than a US gallon and equals approximately 4.54609 liters. The weight under the same standard conditions (4 degrees Celsius) would be about 10.02 pounds (lbs) or roughly 4.546 kilograms (kg).

Summary

  • US Gallon of Water: Approximately 8.34 pounds (3.785 kilograms) under standard conditions.
  • Imperial Gallon of Water: Approximately 10.02 pounds (4.546 kilograms) under standard conditions.

It’s essential to consider these small variations if precise measurements are required, especially in scientific and industrial applications. However, for most practical everyday purposes, remembering that a US gallon of water weighs about 8.34 pounds is sufficiently accurate.