Dimensions Converter
Enter length, width, and height once. Get every side converted between metric and imperial, plus the area and volume — for boxes, rooms, tanks, and parcels.
Enter a length, width, and height above to see the conversions.
Volume
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Common sizes, ready to convert
Each link opens the converter pre-filled with one common object.
Converting dimensions — common questions
How do I convert length, width, and height all at once?
Type the three measurements into the length, width, and height fields, then choose the unit you measured in — millimetres, centimetres, metres, inches, or feet. The converter instantly shows each side in every other unit in one table, so you do not have to convert them one by one. It also works out the area and volume from the same numbers.
How do I find the volume from length × width × height?
Volume is simply length multiplied by width multiplied by height, in the same unit. If your sides are in feet the answer is in cubic feet; in inches, cubic inches. The converter does this for you and also shows the volume in cubic metres, litres, and US gallons, so you can read it in whichever unit suits the job.
What is the difference between area and volume?
Area measures a flat surface — length times width — and is given in square units like square feet or square metres. Volume measures the space inside a three-dimensional object — length times width times height — and is given in cubic units like cubic feet or litres. This tool reports the base area (the footprint), the total surface area of all six faces, and the volume.
How many litres are in a cubic foot or cubic metre?
One cubic foot holds about 28.3 litres, and one cubic metre holds exactly 1,000 litres. A US gallon is about 3.785 litres. The converter shows litres and gallons alongside cubic feet and cubic metres, which is handy for tanks, aquariums, containers, and anything you need to fill.
Can I mix units — some sides in inches and others in feet?
No — enter all three sides in the same unit so the area and volume are correct. If your measurements are in different units, convert them to one unit first. A quick way is to enter a single side here, read its converted value, then use that consistent unit for all three.
How accurate are the conversions?
The conversions use exact factors — one inch is 25.4 millimetres and one foot is 0.3048 metres — so the only rounding is in how the results are displayed. Values are shown to a sensible number of decimals for readability; for precision work, use the exact figures or round at the end of your own calculation rather than from the displayed numbers.