How to Determine Weight Without a Scale

The easiest way to determine weight is with a scale. If you don't have one handy, you can get a relatively accurate estimate using the water displacement method.

Things You'll Need

• bathtub
• grease pencil or tape
• empty gallon of milk or 2-liter soda bottle

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Instructions

• 1

  Fill a bathtub with enough warm water to completely submerge the person.

• 2

  Mark the level of the water with a grease pencil or piece of tape.

• 3

  Submerge the person in the bathtub. Be careful not to spill any water.

• 4

  Remove the water in the bathtub using an empty milk container (1 gallon) or soda bottle (2 liters) until the water returns to the original level marked by the tape or pencil. Record how much water you remove.

• 5

  Multiple the number of gallons removed by 8.33 pounds. Multiple the number of liters removed by 2.2046 pounds. If using the metric system, multiple the number of gallons removed by 3.778 kg. Multiple the number of liters by 1 kg. Because the density of the human body is roughly equal to water (1 gram per cubic centimeter), you now have the weight of the person.