DIY Drawer Calculator: Get Cutting Dimensions and Guide Placement

Why use a drawer calculator?

Assembling a drawer seems simple until you have to account for every millimeter. Between the thickness of the edging, the clearance needed for telescopic slides, and calculating the gaps between the drawer fronts, mistakes are just around the corner.

I created this tool to help you move from design to cutting with confidence. Whether you’re using inexpensive roller guides or advanced systems like Blum Under-mount, this script will do the hard math for you.

Materia | Drawer Pro

System of Measurement:

Altezza Vano

Larghezza Vano

Numero Cassetti:

Fuga Frontali

Spessore Guida (singola):

Inserisci spessore:

Spessore del Frontale

Spessore Struttura

Bordatura dei frontali:

How to Use the Calculator Correctly

Measure the space

Enter the height and internal width of the cabinet (the “opening” where the drawer will go). Use a caliper or a precision tape measure.

Choose the type of guide

Every driver needs their own space (tolerance):

Roller/Telescopic Guides: Require approximately 12.5 mm – 12.7 mm per side.
Under-mount guides: They disappear beneath the drawer and require less side clearance (about 7 mm on each side), but they involve more complex calculations for the bottom.

Don't forget the edging

If you use laminated or veneered panels, the edge adds thickness. If you enter 0.6 mm into the calculator, the script will automatically subtract 1.2 mm from the total length of the wood to be cut (0.6 mm per side). This ensures that the finished front panel is exactly the size you want.

🛠️ Assembly Guide: Cabinet vs. Cabinet

To ensure the drawer slides smoothly, the two parts of the track must be perfectly parallel and at the same height.

On the drawer front (the movable part)

Perché: Questo ti dà un riferimento certo e rende il cassetto più stabile.
Exception (Under-mount): If you use Blum Movento or Tandem-type slides, the slide is not screwed to the side but “wraps around” the bottom of the drawer. In this case, you will need to create a recess in the back panel of the drawer according to the manufacturer's technical specifications.

Inside the Cabinet (The Fixed Part)

The calculator has provided you with the center-of-the-wheel height. Here's how to use it:

Use a pencil to mark the indicated height on the two inner walls of the cabinet, starting from the bottom.
Draw a perfectly level horizontal line.
Position the cabinet track so that the center holes in the track align with the line you drew.
Setback: The track should not be mounted flush with the outer edge of the cabinet; instead, it must be set back by a distance equal to the thickness of the front panel plus 2 mm for safety. For example, if your front panel is 20 mm thick, mount the track 22 mm from the outer edge.

Tips from Materia Woodcraft for Perfect Drawers

The 70% rule: For a balanced look, the height of the drawer’s inner body should be about 70–80% of the height of the front panel.

It’s all about being square: If the cabinet isn’t perfectly square, the slides will jam. Always check the cabinet’s diagonal measurements before assembling.

Pilot holes: Always use a center drill bit or make a small pilot hole for the guide screws. If the screw “pulls” the wood sideways as it goes in, the guide will shift by a millimeter and the drawer will be misaligned.