Size to Weight Calculator (Rectangular Box)
This size to weight calculator lets you determine how much a rectangular box (e.g., a brick, book, door, companion cube, etc.) weighs based on size and density. It can also find an object's density, provided you know its volume and weight. For example, if you have a brick with dimensions of 92 × 57 × 203 millimeters and a density of 2400 kg/m³, you'd find out that the weight of that object is 2.555 kg.
FAQs
How do I find the weight of a box without a scale?
To find the weight of a box without a scale, you can use the relationship between mass and volume: mass = density × volume.
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Start by measuring the dimensions of the box. 
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Find the box's volume by multiplying together the lengths of the three sides. 
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Estimate or find the density of the material of interest. 
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Make sure that the units agree (for example, use cubic meters for the volume and kilograms per cubic meter for the density), and calculate the mass using: 
 mass = density × volume.
Or to save time, use Omni Calculator's size to weight calculator.
What is the weight of a cube of iron with side 40 cm?
The cube weighs approximately 504 kg. To find this result:
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Calculate the volume of the cube: V = l × l × l = 0.4 × 0.4 × 0.4 = 0.064 m³ 
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Identify the density of iron: d = 7874 kg/m³. 
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Find the mass using: 
 mass = density × volume = 7874 kg/m³ × 0.064 m³ = 503.94 kg
A cube with a side of 40 cm of iron weighs more than half a ton!
How do I convert from volume to weight?
To convert from volume to weight, you need to know the density of the material you're working with. The density is a measure of the mass of a known volume: the higher the density, the higher the weight of an object of fixed size. You can find the density of many materials online or measure it yourself from a sample.
Is weight proportional to size?
Yes, weight and size are proportional — at least if you consider the same material. The constant of proportionality is known as density, a property of matter that characterizes the weight of a given volume.