Shelf Sag Tables - 12" Deep Shelves
These tables contain comparative shelf sag measurements for 12" deep
shelves ranging in width from 30" to 54". Six types of shelving
materials (all 3/4" thick), three shelf loads (20, 30, 40 pounds per linear
foot), and several shelf support techniques are represented. Sag
measurements are to the nearest hundredth of an inch. As a general
guideline, shelf sag should be 0.10" or less.
8" shelves |
12" shelves |
16" shelves |
About these sag measurements
Shelf Width: 30"
(Optimal sag: 0.05" or less, excessive: 0.13"+ )
| End Support |
Front Support |
Rear Support |
Lbs per ft |
Lbs total |
MDF |
Plywood |
Pine |
Poplar |
Cherry |
Oak |
| Float |
No |
No |
20 |
50 |
.04 |
.03 |
.02 |
.02 |
.02 |
.02 |
| Float |
No |
No |
30 |
75 |
.08 |
.05 |
.03 |
.03 |
.03 |
.03 |
| Float |
No |
No |
40 |
100 |
.11 |
.07 |
.05 |
.04 |
.05 |
.05 |
| Fixed |
No |
No |
20 |
50 |
.04 |
.03 |
.03 |
.02 |
.03 |
.02 |
| Fixed |
No |
No |
30 |
75 |
.06 |
.04 |
.04 |
.03 |
.05 |
.02 |
| Fixed |
No |
No |
40 |
100 |
.07 |
.05 |
.05 |
.04 |
.01 |
.04 |
| Fixed |
Yes |
No |
20 |
50 |
.02 |
.01 |
.01 |
.01 |
.01 |
.01 |
| Fixed |
Yes |
No |
30 |
75 |
.03 |
.01 |
.01 |
.01 |
.02 |
.01 |
| Fixed |
Yes |
No |
40 |
100 |
.04 |
.02 |
.02 |
.02 |
.02 |
.02 |
| Fixed |
No |
Yes |
20 |
50 |
.03 |
.03 |
.03 |
.02 |
.02 |
.02 |
| Fixed |
No |
Yes |
30 |
75 |
.04 |
.04 |
.03 |
.03 |
.03 |
.03 |
| Fixed |
No |
Yes |
40 |
100 |
.05 |
.05 |
.05 |
.04 |
.04 |
.04 |
| Fixed |
Yes |
Yes |
20 |
50 |
.01 |
.01 |
.01 |
.01 |
.01 |
.01 |
| Fixed |
Yes |
Yes |
30 |
75 |
.01 |
.01 |
.01 |
.01 |
.01 |
.01 |
| Fixed |
Yes |
Yes |
40 |
100 |
.02 |
.02 |
.02 |
.02 |
.01 |
.02 |
Shelf Width: 36"
(Optimal sag: 0.06" or less, excessive: 0.18"+)
| End Support |
Front Support |
Rear Support |
Lbs per ft |
Lbs total |
MDF |
Plywood |
Pine |
Poplar |
Cherry |
Oak |
| Float |
No |
No |
20 |
60 |
.14 |
.07 |
.04 |
.05 |
.06 |
.05 |
| Float |
No |
No |
30 |
90 |
.22 |
.10 |
.06 |
.06 |
.08 |
.06 |
| Float |
No |
No |
40 |
120 |
.32 |
.14 |
.10 |
.09 |
.11 |
.08 |
| Fixed |
No |
No |
20 |
60 |
.08 |
.04 |
.05 |
.04 |
.04 |
.03 |
| Fixed |
No |
No |
30 |
90 |
.12 |
.06 |
.06 |
.05 |
.05 |
.04 |
| Fixed |
No |
No |
40 |
120 |
.18 |
.09 |
.09 |
.07 |
.08 |
.07 |
| Fixed |
Yes |
No |
20 |
60 |
.04 |
.02 |
.02 |
.02 |
.02 |
.02 |
| Fixed |
Yes |
No |
30 |
90 |
.06 |
.03 |
.02 |
.02 |
.03 |
.02 |
| Fixed |
Yes |
No |
40 |
120 |
.09 |
.05 |
.04 |
.03 |
.04 |
.03 |
| Fixed |
No |
Yes |
20 |
60 |
.05 |
.04 |
.04 |
.02 |
.03 |
.03 |
| Fixed |
No |
Yes |
30 |
90 |
.06 |
.05 |
.05 |
.04 |
.04 |
.04 |
| Fixed |
No |
Yes |
40 |
120 |
.08 |
.07 |
.07 |
.05 |
.05 |
.05 |
| Fixed |
Yes |
Yes |
20 |
60 |
.02 |
.01 |
.01 |
.01 |
.02 |
.01 |
| Fixed |
Yes |
Yes |
30 |
90 |
.03 |
.02 |
.02 |
.02 |
.02 |
.02 |
| Fixed |
Yes |
Yes |
40 |
120 |
.05 |
.03 |
.03 |
.03 |
.03 |
.03 |
Shelf Width: 42"
(Optimal sag: 0.07" or less, excessive 0.21"+)
| End Support |
Front Support |
Rear Support |
Lbs per ft |
Lbs total |
MDF |
Plywood |
Pine |
Poplar |
Cherry |
Oak |
| Float |
No |
No |
20 |
70 |
.28 |
.13 |
.08 |
.07 |
.08 |
.07 |
| Float |
No |
No |
30 |
105 |
.43 |
.18 |
.15 |
.13 |
.12 |
.10 |
| Float |
No |
No |
40 |
140 |
.58 |
.24 |
.21 |
.17 |
.17 |
.13 |
| Fixed |
No |
No |
20 |
70 |
.15 |
.10 |
.09 |
.06 |
.08 |
.05 |
| Fixed |
No |
No |
30 |
105 |
.22 |
.15 |
.14 |
.10 |
.10 |
.09 |
| Fixed |
No |
No |
40 |
140 |
.30 |
.20 |
.18 |
.13 |
.13 |
.12 |
| Fixed |
Yes |
No |
20 |
70 |
.07 |
.05 |
.04 |
.03 |
.04 |
.04 |
| Fixed |
Yes |
No |
30 |
105 |
.11 |
.06 |
.07 |
.05 |
.05 |
.05 |
| Fixed |
Yes |
No |
40 |
140 |
.16 |
.10 |
.10 |
.08 |
.07 |
.06 |
| Fixed |
No |
Yes |
20 |
70 |
.08 |
.07 |
.07 |
.05 |
.05 |
.05 |
| Fixed |
No |
Yes |
30 |
105 |
.11 |
.11 |
.09 |
.08 |
.07 |
.07 |
| Fixed |
No |
Yes |
40 |
140 |
.13 |
.13 |
.12 |
.10 |
.09 |
.09 |
| Fixed |
Yes |
Yes |
20 |
70 |
.04 |
.03 |
.03 |
.03 |
.02 |
.02 |
| Fixed |
Yes |
Yes |
30 |
105 |
.05 |
.04 |
.04 |
.04 |
.03 |
.03 |
| Fixed |
Yes |
Yes |
40 |
140 |
.07 |
.05 |
.05 |
.05 |
.05 |
.04 |
Shelf Width: 48"
(Optimal sag: 0.08" or less, excessive: 0.24"+)
| End Support |
Front Support |
Rear Support |
Lbs per ft |
Lbs total |
MDF |
Plywood |
Pine |
Poplar |
Cherry |
Oak |
| Float |
No |
No |
20 |
80 |
.48 |
.16 |
.14 |
.14 |
.14 |
.12 |
| Float |
No |
No |
30 |
120 |
.76 |
.30 |
.23 |
.24 |
.21 |
.17 |
| Float |
No |
No |
40 |
160 |
1.04 |
.39 |
.34 |
.30 |
.29 |
.23 |
| Fixed |
No |
No |
20 |
80 |
.23 |
.12 |
.12 |
.11 |
.10 |
.08 |
| Fixed |
No |
No |
30 |
120 |
.36 |
.19 |
.19 |
.17 |
.16 |
.14 |
| Fixed |
No |
No |
40 |
160 |
.49 |
.26 |
.25 |
.22 |
.21 |
.18 |
| Fixed |
Yes |
No |
20 |
80 |
.14 |
.06 |
.07 |
.04 |
.04 |
.03 |
| Fixed |
Yes |
No |
30 |
120 |
.22 |
.11 |
.11 |
.08 |
.08 |
.06 |
| Fixed |
Yes |
No |
40 |
160 |
.30 |
.16 |
.15 |
.12 |
.11 |
.08 |
| Fixed |
No |
Yes |
20 |
80 |
.10 |
.10 |
.09 |
.08 |
.08 |
.06 |
| Fixed |
No |
Yes |
30 |
120 |
.13 |
.16 |
.13 |
.11 |
.10 |
.09 |
| Fixed |
No |
Yes |
40 |
160 |
.16 |
.20 |
.17 |
.14 |
.13 |
.12 |
| Fixed |
Yes |
Yes |
20 |
80 |
.06 |
.04 |
.04 |
.03 |
.03 |
.03 |
| Fixed |
Yes |
Yes |
30 |
120 |
.08 |
.07 |
.06 |
.05 |
.07 |
.05 |
| Fixed |
Yes |
Yes |
40 |
160 |
.10 |
.09 |
.08 |
.07 |
.08 |
.07 |
Shelf Width: 54"
(Optimal sag: 0.09" or less, excessive: 0.27"+)
| End Support |
Front Support |
Rear Support |
Lbs per ft |
Lbs total |
MDF |
Plywood |
Pine |
Poplar |
Cherry |
Oak |
| Float |
No |
No |
20 |
90 |
.70 |
.27 |
.27 |
.20 |
.22 |
.16 |
| Float |
No |
No |
30 |
135 |
1.23 |
.50 |
.44 |
.34 |
.34 |
.25 |
| Float |
No |
No |
40 |
180 |
1.8 |
.69 |
.60 |
.46 |
.47 |
.34 |
| Fixed |
No |
No |
20 |
90 |
.31 |
.20 |
.18 |
.14 |
.14 |
.12 |
| Fixed |
No |
No |
30 |
135 |
.55 |
.35 |
.29 |
.23 |
.22 |
.18 |
| Fixed |
No |
No |
40 |
180 |
.84 |
.44 |
.41 |
.33 |
.32 |
.26 |
| Fixed |
Yes |
No |
20 |
90 |
.13 |
.09 |
.09 |
.08 |
.05 |
.05 |
| Fixed |
Yes |
No |
30 |
135 |
.25 |
.19 |
.14 |
.14 |
.11 |
.10 |
| Fixed |
Yes |
No |
40 |
180 |
.40 |
.28 |
.21 |
.20 |
.19 |
.15 |
| Fixed |
No |
Yes |
20 |
90 |
.09 |
.15 |
.13 |
.10 |
.08 |
.08 |
| Fixed |
No |
Yes |
30 |
135 |
.14 |
.22 |
.18 |
.15 |
.14 |
.11 |
| Fixed |
No |
Yes |
40 |
180 |
.18 |
.28 |
.23 |
.18 |
.19 |
.15 |
| Fixed |
Yes |
Yes |
20 |
90 |
.05 |
.06 |
.08 |
.06 |
.03 |
.04 |
| Fixed |
Yes |
Yes |
30 |
135 |
.08 |
.12 |
.19 |
.09 |
.07 |
.08 |
| Fixed |
Yes |
Yes |
40 |
180 |
.11 |
.18 |
.15 |
.12 |
.10 |
.10 |
|