Shelf Weight Capacity Calculator
Calculate the maximum weight a shelf can hold based on material, length, depth, and support spacing.
Avoid overloaded shelves.
Maximum Weight Capacity
Shelf weight capacity depends on the material, thickness, span between supports, and depth. Longer unsupported spans dramatically reduce capacity.
Approximate max load per shelf (3/4 inch / 19mm thick, 12 in / 30 cm deep):
| Material | 24 in (60 cm) span | 36 in (90 cm) span | 48 in (120 cm) span |
|---|---|---|---|
| Solid hardwood (oak) | 100 lbs (45 kg) | 60 lbs (27 kg) | 35 lbs (16 kg) |
| Plywood (3/4 in) | 80 lbs (36 kg) | 45 lbs (20 kg) | 25 lbs (11 kg) |
| MDF | 60 lbs (27 kg) | 30 lbs (14 kg) | 15 lbs (7 kg) |
| Particle board | 40 lbs (18 kg) | 20 lbs (9 kg) | 10 lbs (4.5 kg) |
| Glass (3/8 in) | 30 lbs (14 kg) | 15 lbs (7 kg) | 8 lbs (3.6 kg) |
Key rule: Doubling the span quarters the load capacity. Adding a center support quadruples it.
Tip: For heavy items like books (~25 lbs per linear foot), keep spans under 32 inches for hardwood and 24 inches for MDF.