Drawer Slide Calculator
Calculate drawer slide length, side clearance, and bottom clearance for cabinet projects.
Covers full-extension, soft-close, and undermount slide types.
Drawer Slide Size
Drawer slides must be matched to both the drawer length and the load they will carry. Selecting the wrong slide causes sagging, binding, or complete failure over time.
Key measurements:
Slide Length = Drawer Box Depth − 1 inch (standard)
Required Weight Rating ≥ Maximum Expected Load (with 2× safety factor)
Drawer length selection:
- Slides are sold in 2-inch increments (12", 14", 16", 18", 20", 22", 24", 28")
- Choose the next size down from drawer depth (e.g., 22" drawer → 20" slide)
- Full-extension slides allow the drawer to open 100% of its depth
- Soft-close undermount slides typically require the drawer to be 1/2" narrower on each side
Weight rating guidelines:
| Application | Recommended Rating |
|---|---|
| Bedroom dresser | 75–100 lbs |
| Kitchen drawer (utensils) | 100–150 lbs |
| File cabinet | 100–150 lbs |
| Heavy tool drawer | 200–500 lbs |
| Industrial / server rack | 500–1,000 lbs |
Safety factor rule: Always choose a slide rated at 2× the maximum expected load. A 50-lb load needs a 100-lb-rated slide.
Worked example: A kitchen drawer 20 inches deep, expected to hold 35 lbs of pots and lids:
- Slide length: 18" (one size down from 20")
- Required rating: 35 × 2 = 70 lbs minimum → choose 100 lb rated slides
- Type: full-extension, soft-close undermount for a flush, premium feel
Common mounting types:
- Side-mount: Easiest to install, most common
- Undermount: Hidden from view, requires precise cabinet floor clearance
- Center-mount: For lightweight, vintage-style drawers only