Shelf Pin Spacing Calculator
Adjustable shelving uses a column of evenly spaced pin holes in each cabinet side. To plan the layout you need the panel height, an offset kept clear at the top and bottom, and your jig's pin spacing. This calculator works out how many holes fit, the run they cover, and confirms the spacing, so you can drill a clean, repeatable pattern that lets shelves move in even steps. Use the same plan on every panel so shelves sit level.
Shelf pin spacing formula
usable run = panel height - 2 * offset
number of holes = floor(usable run / pitch) + 1
run covered = (number of holes - 1) * pitch
The usable run is the panel minus the offsets at both ends. Dividing by the pitch and adding one for the first hole gives the count; the run covered is the distance from the first hole to the last.
Worked example
A 30 inch panel with a 3 inch offset at each end has a usable run of 30 - 6 = 24 inches. At 1.25 inch pitch: floor(24 / 1.25) + 1 = floor(19.2) + 1 = 19 + 1 = 20 holes. Run covered = (20 - 1) * 1.25 = 23.75 inches, leaving a small even margin within the offset zone.
Shelf pin spacing: frequently asked questions
What spacing is standard for shelf pin holes?
A common system uses 32 mm spacing (the European 32 mm cabinetmaking system), which is about 1.26 inches. Many jigs use 1 inch or 1.25 inch spacing instead. The spacing you choose is the pin pitch; this calculator uses the value you enter so it works with any jig.
How many shelf pin holes will I drill?
The number of holes in a vertical run equals the usable run length divided by the spacing, plus one for the first hole, rounded down. With a start offset from the top and bottom you reduce the usable run accordingly. This calculator returns the hole count and the actual run the holes cover.
Why use a start offset?
Holes too close to the top or bottom of a cabinet side are not useful and can weaken the panel near joinery. A start offset, often a few inches from each end, keeps holes within the practical adjustment range. Enter the offset you want kept clear at the top and bottom.
Should both sides match?
Yes. For a shelf to sit level, the pin holes on the left and right sides, and on the front and back columns, must be at identical heights. Using a single jig referenced from the same end on every panel keeps them aligned. Plan the pattern once and repeat it consistently.
Sources and method
- The hole count is a standard evenly-spaced division of a run length. It is a geometric calculation, not a sourced figure. The 32 mm cabinet system is an industry convention; enter your own jig pitch.
- National Institute of Standards and Technology: Office of Weights and Measures (length units).
Reviewed by the CalculatorHub team, edited by James Graham, 19 June 2026. See our methodology.