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Glossary » Beams » Simply Supported » Uniformly Distributed Load » Two Equal Spans » Wide Flange Steel I Beam » W12 × 120
Wide Flange Steel I Beam | Single Span | Two Equal Spans | Three Equal Spans | Four Equal Spans

For a simply supported beam in two equal spans, we compute the displacement at the middle of each span w_mid and the maximum normal stress stress_max occuring at the center support of the beam.
The tabulated data listed in this page are calculated based on the area moment of inertia (Ixx = 1070 in4) for the W12 × 120 Wide Flange Steel I Beam and the typical Young's modulus (E = 3.046 × 107 psi) of steels. Note that the typical yielding stress Yield of steels can range from 1.015 × 104 to 2.970 × 105 psi. The purpose of this page is to give a rough estimation of the load-bearing capacity of this particular beam, rather than a guideline for designing actual building structures. Please check your local building codes for regulatory requirements.
Note: The weight of the beam itself is not included in the calculation.
L = 3 ft
L = 5 ft
L = 10 ft
L = 15 ft
L = 20 ft
L = 25 ft
L = 30 ft
L = 40 ft
L = 50 ft
L = 60 ft
L = 70 ft
L = 80 ft
L = 90 ft
L = 100 ft
L = 125 ft
   
Steel I Beam: W12 × 120 (Wide Flange 12 inch tall × 120 lbf/ft)
L = 3.00 ft
P (lbf/ft) w_max (in) stress_max (psi)
120 2.68 × 10-6 9.93
200 4.47 × 10-6 16.6
300 6.71 × 10-6 24.8
400 8.95 × 10-6 33.1
500 1.12 × 10-5 41.4
600 1.34 × 10-5 49.7
700 1.57 × 10-5 57.9
800 1.79 × 10-5 66.2
900 2.01 × 10-5 74.5
1000 2.24 × 10-5 82.8
2000 4.47 × 10-5 166
3000 6.71 × 10-5 248
4000 8.95 × 10-5 331
5000 1.12 × 10-4 414
6000 1.34 × 10-4 497
7000 1.57 × 10-4 579
8000 1.79 × 10-4 662
9000 2.01 × 10-4 745
1.00 × 104 2.24 × 10-4 828
2.00 × 104 4.47 × 10-4 1660
3.00 × 104 6.71 × 10-4 2480
4.00 × 104 8.95 × 10-4 3310
5.00 × 104 0.00112 4140
6.00 × 104 0.00134 4970
7.00 × 104 0.00157 5790
8.00 × 104 0.00179 6620
9.00 × 104 0.00201 7450
1.00 × 105 0.00224 8280
2.00 × 105 0.00447 1.66 × 104
3.00 × 105 0.00671 2.48 × 104
4.00 × 105 0.00895 3.31 × 104
5.00 × 105 0.0112 4.14 × 104
6.00 × 105 0.0134 4.97 × 104
7.00 × 105 0.0157 5.79 × 104
8.00 × 105 0.0179 6.62 × 104
9.00 × 105 0.0201 7.45 × 104
1.00 × 106 0.0224 8.28 × 104
2.00 × 106 0.0447 1.66 × 105
3.00 × 106 0.0671 2.48 × 105
3.59 × 106 0.0803 2.97 × 105
Steel I Beam: W12 × 120 (Wide Flange 12 inch tall × 120 lbf/ft)
L = 5.00 ft
P (lbf/ft) w_max (in) stress_max (psi)
120 2.07 × 10-5 27.6
200 3.45 × 10-5 46.0
300 5.18 × 10-5 69.0
400 6.90 × 10-5 92.0
500 8.63 × 10-5 115
600 1.04 × 10-4 138
700 1.21 × 10-4 161
800 1.38 × 10-4 184
900 1.55 × 10-4 207
1000 1.73 × 10-4 230
2000 3.45 × 10-4 460
3000 5.18 × 10-4 690
4000 6.90 × 10-4 920
5000 8.63 × 10-4 1150
6000 0.00104 1380
7000 0.00121 1610
8000 0.00138 1840
9000 0.00155 2070
1.00 × 104 0.00173 2300
2.00 × 104 0.00345 4600
3.00 × 104 0.00518 6900
4.00 × 104 0.00690 9200
5.00 × 104 0.00863 1.15 × 104
6.00 × 104 0.0104 1.38 × 104
7.00 × 104 0.0121 1.61 × 104
8.00 × 104 0.0138 1.84 × 104
9.00 × 104 0.0155 2.07 × 104
1.00 × 105 0.0173 2.30 × 104
2.00 × 105 0.0345 4.60 × 104
3.00 × 105 0.0518 6.90 × 104
4.00 × 105 0.0690 9.20 × 104
5.00 × 105 0.0863 1.15 × 105
6.00 × 105 0.104 1.38 × 105
7.00 × 105 0.121 1.61 × 105
8.00 × 105 0.138 1.84 × 105
9.00 × 105 0.155 2.07 × 105
1.00 × 106 0.173 2.30 × 105
1.29 × 106 0.223 2.97 × 105
Steel I Beam: W12 × 120 (Wide Flange 12 inch tall × 120 lbf/ft)
L = 10.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
120 3.31 × 10-4 110
200 5.52 × 10-4 184
300 8.28 × 10-4 276
400 0.00110 368
500 0.00138 460
600 0.00166 552
700 0.00193 644
800 0.00221 736
900 0.00249 828
1000 0.00276 920
2000 0.00552 1840
3000 0.00828 2760
4000 0.0110 3680
5000 0.0138 4600
6000 0.0166 5520
7000 0.0193 6440
8000 0.0221 7360
9000 0.0249 8280
1.00 × 104 0.0276 9200
2.00 × 104 0.0552 1.84 × 104
3.00 × 104 0.0828 2.76 × 104
4.00 × 104 0.110 3.68 × 104
5.00 × 104 0.138 4.60 × 104
6.00 × 104 0.166 5.52 × 104
7.00 × 104 0.193 6.44 × 104
8.00 × 104 0.221 7.36 × 104
9.00 × 104 0.249 8.28 × 104
1.00 × 105 0.276 9.20 × 104
2.00 × 105 0.552 1.84 × 105
3.00 × 105 0.828 2.76 × 105
3.23 × 105 0.892 2.97 × 105
Steel I Beam: W12 × 120 (Wide Flange 12 inch tall × 120 lbf/ft)
L = 15.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
120 0.00168 248
200 0.00280 414
300 0.00419 621
400 0.00559 828
500 0.00699 1030
600 0.00839 1240
700 0.00979 1450
800 0.0112 1660
900 0.0126 1860
1000 0.0140 2070
2000 0.0280 4140
3000 0.0419 6210
4000 0.0559 8280
5000 0.0699 1.03 × 104
6000 0.0839 1.24 × 104
7000 0.0979 1.45 × 104
8000 0.112 1.66 × 104
9000 0.126 1.86 × 104
1.00 × 104 0.140 2.07 × 104
2.00 × 104 0.280 4.14 × 104
3.00 × 104 0.419 6.21 × 104
4.00 × 104 0.559 8.28 × 104
5.00 × 104 0.699 1.03 × 105
6.00 × 104 0.839 1.24 × 105
7.00 × 104 0.979 1.45 × 105
8.00 × 104 1.12 1.66 × 105
9.00 × 104 1.26 1.86 × 105
1.00 × 105 1.40 2.07 × 105
1.44 × 105 2.01 2.97 × 105
Steel I Beam: W12 × 120 (Wide Flange 12 inch tall × 120 lbf/ft)
L = 20.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
120 0.00530 441
200 0.00884 736
300 0.0133 1100
400 0.0177 1470
500 0.0221 1840
600 0.0265 2210
700 0.0309 2570
800 0.0353 2940
900 0.0398 3310
1000 0.0442 3680
2000 0.0884 7360
3000 0.133 1.10 × 104
4000 0.177 1.47 × 104
5000 0.221 1.84 × 104
6000 0.265 2.21 × 104
7000 0.309 2.57 × 104
8000 0.353 2.94 × 104
9000 0.398 3.31 × 104
1.00 × 104 0.442 3.68 × 104
2.00 × 104 0.884 7.36 × 104
3.00 × 104 1.33 1.10 × 105
4.00 × 104 1.77 1.47 × 105
5.00 × 104 2.21 1.84 × 105
6.00 × 104 2.65 2.21 × 105
7.00 × 104 3.09 2.57 × 105
8.00 × 104 3.53 2.94 × 105
8.07 × 104 3.57 2.97 × 105
Steel I Beam: W12 × 120 (Wide Flange 12 inch tall × 120 lbf/ft)
L = 25.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
120 0.0129 690
200 0.0216 1150
300 0.0324 1720
400 0.0431 2300
500 0.0539 2870
600 0.0647 3450
700 0.0755 4020
800 0.0863 4600
900 0.0971 5170
1000 0.108 5750
2000 0.216 1.15 × 104
3000 0.324 1.72 × 104
4000 0.431 2.30 × 104
5000 0.539 2.87 × 104
6000 0.647 3.45 × 104
7000 0.755 4.02 × 104
8000 0.863 4.60 × 104
9000 0.971 5.17 × 104
1.00 × 104 1.08 5.75 × 104
2.00 × 104 2.16 1.15 × 105
3.00 × 104 3.24 1.72 × 105
4.00 × 104 4.31 2.30 × 105
5.00 × 104 5.39 2.87 × 105
5.17 × 104 5.57 2.97 × 105
Steel I Beam: W12 × 120 (Wide Flange 12 inch tall × 120 lbf/ft)
L = 30.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
120 0.0268 993
200 0.0447 1660
300 0.0671 2480
400 0.0895 3310
500 0.112 4140
600 0.134 4970
700 0.157 5790
800 0.179 6620
900 0.201 7450
1000 0.224 8280
2000 0.447 1.66 × 104
3000 0.671 2.48 × 104
4000 0.895 3.31 × 104
5000 1.12 4.14 × 104
6000 1.34 4.97 × 104
7000 1.57 5.79 × 104
8000 1.79 6.62 × 104
9000 2.01 7.45 × 104
1.00 × 104 2.24 8.28 × 104
2.00 × 104 4.47 1.66 × 105
3.00 × 104 6.71 2.48 × 105
3.59 × 104 8.03 2.97 × 105
Steel I Beam: W12 × 120 (Wide Flange 12 inch tall × 120 lbf/ft)
L = 40.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
120 0.0848 1770
200 0.141 2940
300 0.212 4410
400 0.283 5890
500 0.353 7360
600 0.424 8830
700 0.495 1.03 × 104
800 0.566 1.18 × 104
900 0.636 1.32 × 104
1000 0.707 1.47 × 104
2000 1.41 2.94 × 104
3000 2.12 4.41 × 104
4000 2.83 5.89 × 104
5000 3.53 7.36 × 104
6000 4.24 8.83 × 104
7000 4.95 1.03 × 105
8000 5.66 1.18 × 105
9000 6.36 1.32 × 105
1.00 × 104 7.07 1.47 × 105
1.86 × 104 13.1 2.73 × 105
Steel I Beam: W12 × 120 (Wide Flange 12 inch tall × 120 lbf/ft)
L = 50.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
120 0.207 2760
200 0.345 4600
300 0.518 6900
400 0.690 9200
500 0.863 1.15 × 104
600 1.04 1.38 × 104
700 1.21 1.61 × 104
800 1.38 1.84 × 104
900 1.55 2.07 × 104
1000 1.73 2.30 × 104
2000 3.45 4.60 × 104
3000 5.18 6.90 × 104
4000 6.90 9.20 × 104
5000 8.63 1.15 × 105
6000 10.4 1.38 × 105
7000 12.1 1.61 × 105
7600 13.1 1.75 × 105
Steel I Beam: W12 × 120 (Wide Flange 12 inch tall × 120 lbf/ft)
L = 60.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
120 0.429 3970
200 0.716 6620
300 1.07 9930
400 1.43 1.32 × 104
500 1.79 1.66 × 104
600 2.15 1.99 × 104
700 2.51 2.32 × 104
800 2.86 2.65 × 104
900 3.22 2.98 × 104
1000 3.58 3.31 × 104
2000 7.16 6.62 × 104
3000 10.7 9.93 × 104
3670 13.1 1.21 × 105
Steel I Beam: W12 × 120 (Wide Flange 12 inch tall × 120 lbf/ft)
L = 70.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
120 0.796 5410
200 1.33 9010
300 1.99 1.35 × 104
400 2.65 1.80 × 104
500 3.32 2.25 × 104
600 3.98 2.70 × 104
700 4.64 3.15 × 104
800 5.30 3.60 × 104
900 5.97 4.06 × 104
1000 6.63 4.51 × 104
1980 13.1 8.92 × 104
Steel I Beam: W12 × 120 (Wide Flange 12 inch tall × 120 lbf/ft)
L = 80.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
120 1.36 7060
200 2.26 1.18 × 104
300 3.39 1.77 × 104
400 4.52 2.35 × 104
500 5.66 2.94 × 104
600 6.79 3.53 × 104
700 7.92 4.12 × 104
800 9.05 4.71 × 104
900 10.2 5.30 × 104
1000 11.3 5.89 × 104
1160 13.1 6.83 × 104
Steel I Beam: W12 × 120 (Wide Flange 12 inch tall × 120 lbf/ft)
L = 90.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
120 2.17 8940
200 3.62 1.49 × 104
300 5.44 2.23 × 104
400 7.25 2.98 × 104
500 9.06 3.72 × 104
600 10.9 4.47 × 104
700 12.7 5.21 × 104
724 13.1 5.39 × 104
Steel I Beam: W12 × 120 (Wide Flange 12 inch tall × 120 lbf/ft)
L = 100 ft
P (lbf/ft) w_max (in) stress_max (psi)
120 3.31 1.10 × 104
200 5.52 1.84 × 104
300 8.28 2.76 × 104
400 11.0 3.68 × 104
475 13.1 4.37 × 104
Steel I Beam: W12 × 120 (Wide Flange 12 inch tall × 120 lbf/ft)
L = 125 ft
P (lbf/ft) w_max (in) stress_max (psi)
120 8.09 1.72 × 104
195 13.1 2.80 × 104
Additional Information
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FREE Publications
CNC Machining Design Guide

Optimize your designs, reduce machining time, and lower your costs.

Essentials of Manufacturing

Information, coverage of important developments and expert commentary in manufacturing.

3D Scanners

A white paper to assist in the evaluation of 3D scanning hardware solutions.

Selecting the Right 3D Printer

Discover how to choose the right 3D printer for your needs and the key performance attributes to consider.

more publications