Calculate drawer box size from a cabinet opening, or the opening needed for a drawer box, using editable slide clearances in inches or mm.

Editable 1/2 in per side assumption. All gaps are additive.

Interior and butt-joint panel estimate
Blank omits interior/cuts. Assumes front, back, sides and an inset flush-bottom floor of equal thickness.

Related Calculators

Drawer Size Formula

The sizing calculator subtracts the entered clearances from a cabinet opening, or adds them to a drawer box in reverse. Width allowance is twice the clearance per side; height allowance is the top plus bottom gap; depth allowance is the rear gap. These are geometric planning dimensions, subject to the exact hardware specification.

For optional interior capacity, the model uses uniform panel thickness t: internal width = outside width − 2t; internal depth = outside depth − 2t; internal height = outside height − t. This assumes front/back between the sides and an inset floor flush with the bottom edges. Joinery and mounting details can change these dimensions. The following volume formula uses internal measurements.

V = W × D × H

Variables:

  • V is the volume of the drawer (cubic inches)
  • W is the width of the drawer (inches)
  • D is the depth of the drawer (inches)
  • H is the height of the drawer (inches)

To calculate the volume of a drawer, multiply the width by the depth and then by the height.

What is Drawer Volume?

Drawer volume is a measure of the storage capacity of a drawer. It is calculated by multiplying the internal width, depth, and height of the drawer. This measurement is typically used in cabinetry and furniture making to ensure that drawers are the correct size for their intended use.

How to Calculate Drawer Size?

The following steps outline how to calculate the volume of a drawer.

  1. First, measure the internal width (W) of the drawer in inches.
  2. Next, measure the internal depth (D) of the drawer in inches.
  3. Then, measure the internal height (H) of the drawer in inches.
  4. Use the formula V = W * D * H to calculate the volume (V).
  5. After inserting the measurements and calculating the result, check your answer with the calculator above.

Example Problem :

Use the following measurements as an example problem to test your knowledge.

Width (W) = 24 inches

Depth (D) = 18 inches

Height (H) = 6 inches