Common board sizes in mm
Sheet sizes vary more in metric countries than in the US, so check the label or measure before you enter anything.
| Board | Size | Where you find it |
|---|---|---|
| Plywood, MDF | 2440 × 1220 mm | UK, Australia, much of Asia. The metric cousin of 8×4. |
| Plywood, MDF | 2500 × 1250 mm | Continental Europe. |
| Chipboard, MFC | 2800 × 2070 mm | Kitchen and wardrobe makers, cut on a panel saw. |
| Birch plywood | 1525 × 1525 mm | Baltic birch, sometimes sold as 1500 × 1500. |
All four are in the "+ Common size" list above the sheet rows, so you do not have to type them.
The wardrobe example
Two 2000 × 560 mm sides with the grain locked, a 1600 mm divider, top and bottom, three shelves and two plinth strips. The sides set the layout. At 2000 mm they only fit along the 2440 mm length, which leaves a 417 mm strip at the end of the board after the 3 mm kerf and 10 mm trim on both ends. That strip is too narrow for anything here except the plinths, so the wardrobe needs three boards and wastes about a third of them.
Now pick 2800 × 2070 mm from the "+ Common size" list and press Calculate again. With both sizes to choose from it gets the job onto two boards. If your supplier sells the big chipboard sheets, that is worth asking about before you order.
The 10 mm edge trim is there because the example assumes chipboard with knocked edges. On good birch ply you can set it to 0.
Working in millimetres
Enter whole millimetres where you can. Part sizes such as 964 mm (a 1000 mm carcass minus two 18 mm sides) are easier to check on the saw than 964.4. The kerf goes between every pair of parts, so with a 3 mm blade, four parts side by side across a 1220 mm board leave 9 mm less than you might expect. Larger offcuts are labelled with their size on the diagram, so you can see where it went.
The tool keeps your list in the browser. If you also use the inch version, your last list comes with you, in whatever units you left it.