Helpful Shelf Layout Tips
For the most accurate results, measure the inside opening height where the shelves will actually be installed. If the cabinet, bookcase, or wall opening is not perfectly square, check the height in more than one place and use the smallest practical measurement.
Shelf thickness matters when you want the clear spaces between shelves to be equal. Four 3/4-inch shelves, for example, use 3 inches of vertical space before any openings are calculated.
Measuring Your Shelf Marks
Choose whether you want to measure from the bottom or top of the opening, then use the edge or centerline measurements shown in the results. Keep the same reference point for every shelf to avoid cumulative measuring errors.
For U.S. measurements, fractional marks are rounded to the nearest 1/32 inch for practical tape-measure use. Metric results are shown in millimeters for precise workshop layout.
Fixed vs. Adjustable Shelves
This calculator is intended for laying out fixed shelves or determining permanent shelf positions. Adjustable shelf-pin systems use a different type of layout because the hole spacing is predetermined.