Blum Tandem & Movento Undermount Drawer Box Calculator
Calculate exact outside drawer box width, required inside clearance (LW − 42mm / 1-21/32"), cut-list part sizes, bottom panel dimensions, and rear hook notch specs for Blum 563H, 569H, and Movento 763H runners in Metric (mm) or Imperial (inches).
21" = 533mm, 18" = 457mm, 15" = 381mm
5/8" = 15.8mm, 1/2" = 12.7mm
Blum Drawer Box Master Cut List
Outside Drawer Width
589.6 mm
Total finished box width
Required Inside Width
558.0 mm
Exact LW − 42.0 mm
Front/Back Sub-Piece Length
558.0 mm
Butt joint between sides
Bottom Recess & Rear Notch
13 mm Deep × 35 mm
6mm rear hook hole from bottom
Live Front Cross-Section Blueprint (Undermount Clearance)
Blum Tandem 563H & Movento 763H Drawer Box Sizing Chart
Quick workshop reference chart showing exact Inside Width (LW − 42mm / 1-21/32") and Outside Drawer Box Width for 1/2" (12.7mm) and 5/8" (15.9mm) drawer sides.
| Cabinet Opening (LW) | Required Inside Width | Outside Width (1/2" / 12.7mm Sides) | Outside Width (5/8" / 15.9mm Sides) | Rear Notch Depth |
|---|---|---|---|---|
| 15" (381 mm) | 13-11/32" (339 mm) | 14-11/32" (364.4 mm) | 14-19/32" (370.8 mm) | 35 mm (1-3/8") |
| 18" (457 mm) | 16-11/32" (415 mm) | 17-11/32" (440.4 mm) | 17-19/32" (446.8 mm) | 35 mm (1-3/8") |
| 21" (533 mm) | 19-11/32" (491 mm) | 20-11/32" (516.4 mm) | 20-19/32" (522.8 mm) | 35 mm (1-3/8") |
| 24" (610 mm) | 22-11/32" (568 mm) | 23-11/32" (593.4 mm) | 23-19/32" (599.8 mm) | 35 mm (1-3/8") |
| 30" (762 mm) | 28-11/32" (720 mm) | 29-11/32" (745.4 mm) | 29-19/32" (751.8 mm) | 35 mm (1-3/8") |
How to Calculate Blum Undermount Drawer Box Width & Clearances
Unlike side-mount ball bearing slides that reference the outside of the drawer box, Blum Tandem and Movento undermount slides reference the Inside Drawer Box Width. Each runner requires a fixed 21 mm (27/32") deduction per side from the cabinet interior opening width (LW), resulting in a total inside deduction of 42 mm (1-21/32") for 563H/763H runners.
Outside_Drawer_Width = (LW − 42 mm) + (2 × Drawer_Side_Thickness)
Frequently Asked Questions
What is the formula for Blum Tandem inside drawer width?
For all Blum Tandem (563H, 563F, 569H) and Movento (763H, 769H) concealed undermount runners, the required Inside Drawer Box Width (NLW) is consistently Cabinet Opening Width (LW) minus 42 mm (1-21/32 inches). The Outside Drawer Box Width is LW - 42 mm + (2 × Drawer Side Material Thickness).
What is the maximum drawer side thickness for Blum 563H vs 563F slides?
Blum 563H and 763H series runners accept drawer side material from 13 mm to 16 mm (1/2 inch to 5/8 inch) thick. If you build drawer boxes from 19 mm (3/4 inch) stock, you must either use Blum 563F series slides (which require an inside width of LW - 49 mm) or rabbet the bottom inside edges down to 16 mm.
How long should a drawer box be for 21 inch (533mm) Blum Tandem slides?
For standard North American 21 inch (533 mm) Blum Tandem 563H slides, the outside drawer box length (front to back, excluding the false drawer front) must be exactly 21 inches (533 mm) with a 35 mm (1-3/8 inch) rear notch for the T51 locking device.
How deep should the bottom recess be for Blum undermount drawer slides?
The bottom recess underneath the drawer box must be between 12.7 mm (1/2 inch) minimum and 15 mm (19/32 inch) maximum from the bottom edge of the drawer sides to clear the concealed runner profile and locking device.
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