Gridfinity Calculator

Convert your drawer measurements to Gridfinity grid units. Enter the interior dimensions in millimeters; the calculator shows the grid size, the half-grid size, leftover edge space, and the tallest bin the drawer can take.

— Grid (42 mm units)
— Half-grid (21 mm steps)
— Leftover width / depth
— Tallest bin (after ~5 mm baseplate)

Measure the drawer's interior, not the front panel. Grid units round down; the baseplate generator's edge padding absorbs the leftover millimeters.

Plan This Drawer in the Layout Tool →

The Math Behind It

Gridfinity is built on two numbers:

Dimension Unit Rule
Width and depth 42 mm Grid units = floor(mm ÷ 42). Half-bin mode works in 21 mm steps.
Height 7 mm Bin height = units × 7 mm, sitting on a baseplate roughly 5 mm tall.

Example: a 480 × 380 × 70 mm drawer.

The 18 mm of leftover width becomes edge padding on the baseplate, or a 0.5-unit column of half-bins if you'd rather store than pad.

After the Math: Plan the Layout

Numbers tell you the grid; the layout planner tells you what goes where. Enter the same measurements there and it draws the grid for you — then you drag bins onto it, color-code them by category, preview the drawer in 3D, and export a print list with every bin size and filament estimates.

For the bins themselves, the bin generator builds custom sizes with compartments, label tabs, and shaped cutouts, and the sizes reference lists standard dimensions if you're downloading pre-made models instead.

Open the Layout Planner →

Frequently Asked Questions

How do I convert drawer measurements to Gridfinity units?
Divide the drawer's interior width and depth in millimeters by 42 and round down. A 480 mm wide drawer fits 11 grid units (462 mm) with 18 mm left over. The calculator on this page does the math, including half-unit sizes.
What do I do with the leftover millimeters?
Generate a baseplate with edge padding — the baseplate generator can distribute the leftover space to any side as a solid border, so bins still fill the drawer edge to edge. Half-bin mode can also reclaim space in 21 mm steps.
How do I calculate Gridfinity bin height?
Bin heights are multiples of 7 mm, called units (a 3U bin is 21 mm of usable wall). To find the tallest bin a drawer can take, subtract about 5 mm for the baseplate from the interior height and divide by 7, rounding down.
Why 42 mm?
Zack Freedman picked 42 mm as the Gridfinity base unit — big enough for useful bins, small enough for fine-grained layouts, and yes, also the answer to everything. Every Gridfinity bin and baseplate uses multiples of it, which is what makes the whole system interchangeable.
Does this calculator handle half-size bins?
Yes. Half-grid mode works in 21 mm steps, so a 105 mm space fits a 2.5-unit bin. The calculator shows both the whole-unit and half-unit grid for your measurements.