First click (right) top window where it says Length m enter your length. Enter your width the same as above Width m.
Same with Depth m. Important to Remember When Part or Less than a Metre say 0.036mm you can enter .036 or 0.036. But you must have the decimal point, or you'll calculate 36 meters instead of 36mm. Once you have your 3 measurements entered. Click with your mouse the calculate button for your answer in cubic metres. If you are not familiar with metric’s reference: $1.00 = 100 cents. 1.000m = 1,000mm.
Quick example. Length m (2), Width m (2), Depth m (2) = 8m3.
You don't have to refresh the page to re use the calculator. You can change any or all the amounts entered and re use the calculate button.