How this instrument works
A rectangular prism (an ordinary box) has its volume set entirely by three measurements: length, width, and height, multiplied together. There's no shortcut needed and no special case to watch for — the formula is a straight product of the three dimensions, in any order.
This site already has combined Rectangular Prism and Cuboid calculators that return volume, surface area, and (for the cuboid) the interior diagonal all from the same three measurements. This page is a narrower, quicker convenience version for whenever only the volume itself is needed, without the extra figures alongside it.
Because the formula is a pure product, doubling any single dimension exactly doubles the volume — doubling the height of a box doubles how much it holds, with the footprint (length times width) staying exactly the same.
- Enter the box's length into the Length field.
- Enter its width into the Width field.
- Enter its height into the Height field.
- Read Volume: the straight product of all three dimensions.
Worked example — a 3 by 4 by 5 box
A box measuring 3 by 4 by 5 units has a volume of 3×4×5=60 cubic units — no dimension is treated any differently from the others, so the same three numbers multiplied in any order give the identical result.
A cube 2 units on every edge is the special case where all three dimensions match, giving a volume of 2³=8, while a thin slab measuring 1 by 10 by 10 still reaches a volume of 1×10×10=100 despite looking flat, since volume only cares about the product, not how the three lengths are distributed.
Questions
What is the formula for the volume of a rectangular prism?
V = l×w×h, the straight product of the length, width, and height — no other measurement is needed, and the three dimensions can be multiplied in any order without changing the result.
How is this different from the Rectangular Prism or Cuboid calculators on this site?
Those pages return volume, surface area, and (for the cuboid) the interior diagonal together from the same three inputs; this page is a narrower, single-figure version for whenever only the volume itself is needed.
What happens to the volume if I double one dimension?
The volume exactly doubles too — since the formula is a pure product, scaling any single one of the three dimensions by a factor scales the total volume by that same factor, with the other two dimensions unaffected.
Does the order I enter length, width, and height matter?
No — multiplication doesn't care about order, so 3×4×5 gives the identical volume as 5×3×4 or any other arrangement of the same three numbers.
What's the volume of a cube using this calculator?
Enter the same value for length, width, and height — a cube is simply the special case of a rectangular prism where all three dimensions match, and the volume comes out to that shared value cubed.