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Glossary » Beams » Simply Supported » Uniformly Distributed Load » Two Equal Spans » Wide Flange Steel I Beam » W12 × 45
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 = 350 in4) for the W12 × 45 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 × 45 (Wide Flange 12 inch tall × 45 lbf/ft)
L = 3.00 ft
P (lbf/ft) w_max (in) stress_max (psi)
45.0 3.08 × 10-6 10.5
50.0 3.42 × 10-6 11.6
60.0 4.10 × 10-6 14.0
70.0 4.79 × 10-6 16.3
80.0 5.47 × 10-6 18.6
90.0 6.15 × 10-6 20.9
100 6.84 × 10-6 23.3
200 1.37 × 10-5 46.5
300 2.05 × 10-5 69.8
400 2.74 × 10-5 93.0
500 3.42 × 10-5 116
600 4.10 × 10-5 140
700 4.79 × 10-5 163
800 5.47 × 10-5 186
900 6.15 × 10-5 209
1000 6.84 × 10-5 233
2000 1.37 × 10-4 465
3000 2.05 × 10-4 698
4000 2.74 × 10-4 930
5000 3.42 × 10-4 1160
6000 4.10 × 10-4 1400
7000 4.79 × 10-4 1630
8000 5.47 × 10-4 1860
9000 6.15 × 10-4 2090
1.00 × 104 6.84 × 10-4 2330
2.00 × 104 0.00137 4650
3.00 × 104 0.00205 6980
4.00 × 104 0.00274 9300
5.00 × 104 0.00342 1.16 × 104
6.00 × 104 0.00410 1.40 × 104
7.00 × 104 0.00479 1.63 × 104
8.00 × 104 0.00547 1.86 × 104
9.00 × 104 0.00615 2.09 × 104
1.00 × 105 0.00684 2.33 × 104
2.00 × 105 0.0137 4.65 × 104
3.00 × 105 0.0205 6.98 × 104
4.00 × 105 0.0274 9.30 × 104
5.00 × 105 0.0342 1.16 × 105
6.00 × 105 0.0410 1.40 × 105
7.00 × 105 0.0479 1.63 × 105
8.00 × 105 0.0547 1.86 × 105
9.00 × 105 0.0615 2.09 × 105
1.00 × 106 0.0684 2.33 × 105
1.28 × 106 0.0873 2.97 × 105
Steel I Beam: W12 × 45 (Wide Flange 12 inch tall × 45 lbf/ft)
L = 5.00 ft
P (lbf/ft) w_max (in) stress_max (psi)
45.0 2.37 × 10-5 29.1
50.0 2.64 × 10-5 32.3
60.0 3.17 × 10-5 38.8
70.0 3.69 × 10-5 45.2
80.0 4.22 × 10-5 51.7
90.0 4.75 × 10-5 58.1
100 5.28 × 10-5 64.6
200 1.06 × 10-4 129
300 1.58 × 10-4 194
400 2.11 × 10-4 258
500 2.64 × 10-4 323
600 3.17 × 10-4 388
700 3.69 × 10-4 452
800 4.22 × 10-4 517
900 4.75 × 10-4 581
1000 5.28 × 10-4 646
2000 0.00106 1290
3000 0.00158 1940
4000 0.00211 2580
5000 0.00264 3230
6000 0.00317 3880
7000 0.00369 4520
8000 0.00422 5170
9000 0.00475 5810
1.00 × 104 0.00528 6460
2.00 × 104 0.0106 1.29 × 104
3.00 × 104 0.0158 1.94 × 104
4.00 × 104 0.0211 2.58 × 104
5.00 × 104 0.0264 3.23 × 104
6.00 × 104 0.0317 3.88 × 104
7.00 × 104 0.0369 4.52 × 104
8.00 × 104 0.0422 5.17 × 104
9.00 × 104 0.0475 5.81 × 104
1.00 × 105 0.0528 6.46 × 104
2.00 × 105 0.106 1.29 × 105
3.00 × 105 0.158 1.94 × 105
4.00 × 105 0.211 2.58 × 105
4.60 × 105 0.243 2.97 × 105
Steel I Beam: W12 × 45 (Wide Flange 12 inch tall × 45 lbf/ft)
L = 10.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
45.0 3.80 × 10-4 116
50.0 4.22 × 10-4 129
60.0 5.07 × 10-4 155
70.0 5.91 × 10-4 181
80.0 6.75 × 10-4 207
90.0 7.60 × 10-4 233
100 8.44 × 10-4 258
200 0.00169 517
300 0.00253 775
400 0.00338 1030
500 0.00422 1290
600 0.00507 1550
700 0.00591 1810
800 0.00675 2070
900 0.00760 2330
1000 0.00844 2580
2000 0.0169 5170
3000 0.0253 7750
4000 0.0338 1.03 × 104
5000 0.0422 1.29 × 104
6000 0.0507 1.55 × 104
7000 0.0591 1.81 × 104
8000 0.0675 2.07 × 104
9000 0.0760 2.33 × 104
1.00 × 104 0.0844 2.58 × 104
2.00 × 104 0.169 5.17 × 104
3.00 × 104 0.253 7.75 × 104
4.00 × 104 0.338 1.03 × 105
5.00 × 104 0.422 1.29 × 105
6.00 × 104 0.507 1.55 × 105
7.00 × 104 0.591 1.81 × 105
8.00 × 104 0.675 2.07 × 105
9.00 × 104 0.760 2.33 × 105
1.00 × 105 0.844 2.58 × 105
1.15 × 105 0.970 2.97 × 105
Steel I Beam: W12 × 45 (Wide Flange 12 inch tall × 45 lbf/ft)
L = 15.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
45.0 0.00192 262
50.0 0.00214 291
60.0 0.00256 349
70.0 0.00299 407
80.0 0.00342 465
90.0 0.00385 523
100 0.00427 581
200 0.00855 1160
300 0.0128 1740
400 0.0171 2330
500 0.0214 2910
600 0.0256 3490
700 0.0299 4070
800 0.0342 4650
900 0.0385 5230
1000 0.0427 5810
2000 0.0855 1.16 × 104
3000 0.128 1.74 × 104
4000 0.171 2.33 × 104
5000 0.214 2.91 × 104
6000 0.256 3.49 × 104
7000 0.299 4.07 × 104
8000 0.342 4.65 × 104
9000 0.385 5.23 × 104
1.00 × 104 0.427 5.81 × 104
2.00 × 104 0.855 1.16 × 105
3.00 × 104 1.28 1.74 × 105
4.00 × 104 1.71 2.33 × 105
5.00 × 104 2.14 2.91 × 105
5.11 × 104 2.18 2.97 × 105
Steel I Beam: W12 × 45 (Wide Flange 12 inch tall × 45 lbf/ft)
L = 20.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
45.0 0.00608 465
50.0 0.00675 517
60.0 0.00810 620
70.0 0.00946 724
80.0 0.0108 827
90.0 0.0122 930
100 0.0135 1030
200 0.0270 2070
300 0.0405 3100
400 0.0540 4130
500 0.0675 5170
600 0.0810 6200
700 0.0946 7240
800 0.108 8270
900 0.122 9300
1000 0.135 1.03 × 104
2000 0.270 2.07 × 104
3000 0.405 3.10 × 104
4000 0.540 4.13 × 104
5000 0.675 5.17 × 104
6000 0.810 6.20 × 104
7000 0.946 7.24 × 104
8000 1.08 8.27 × 104
9000 1.22 9.30 × 104
1.00 × 104 1.35 1.03 × 105
2.00 × 104 2.70 2.07 × 105
2.87 × 104 3.88 2.97 × 105
Steel I Beam: W12 × 45 (Wide Flange 12 inch tall × 45 lbf/ft)
L = 25.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
45.0 0.0148 727
50.0 0.0165 808
60.0 0.0198 969
70.0 0.0231 1130
80.0 0.0264 1290
90.0 0.0297 1450
100 0.0330 1620
200 0.0660 3230
300 0.0989 4850
400 0.132 6460
500 0.165 8080
600 0.198 9690
700 0.231 1.13 × 104
800 0.264 1.29 × 104
900 0.297 1.45 × 104
1000 0.330 1.62 × 104
2000 0.660 3.23 × 104
3000 0.989 4.85 × 104
4000 1.32 6.46 × 104
5000 1.65 8.08 × 104
6000 1.98 9.69 × 104
7000 2.31 1.13 × 105
8000 2.64 1.29 × 105
9000 2.97 1.45 × 105
1.00 × 104 3.30 1.62 × 105
1.84 × 104 6.06 2.97 × 105
Steel I Beam: W12 × 45 (Wide Flange 12 inch tall × 45 lbf/ft)
L = 30.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
45.0 0.0308 1050
50.0 0.0342 1160
60.0 0.0410 1400
70.0 0.0479 1630
80.0 0.0547 1860
90.0 0.0615 2090
100 0.0684 2330
200 0.137 4650
300 0.205 6980
400 0.274 9300
500 0.342 1.16 × 104
600 0.410 1.40 × 104
700 0.479 1.63 × 104
800 0.547 1.86 × 104
900 0.615 2.09 × 104
1000 0.684 2.33 × 104
2000 1.37 4.65 × 104
3000 2.05 6.98 × 104
4000 2.74 9.30 × 104
5000 3.42 1.16 × 105
6000 4.10 1.40 × 105
7000 4.79 1.63 × 105
8000 5.47 1.86 × 105
9000 6.15 2.09 × 105
1.00 × 104 6.84 2.33 × 105
1.28 × 104 8.73 2.97 × 105
Steel I Beam: W12 × 45 (Wide Flange 12 inch tall × 45 lbf/ft)
L = 40.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
45.0 0.0973 1860
50.0 0.108 2070
60.0 0.130 2480
70.0 0.151 2890
80.0 0.173 3310
90.0 0.195 3720
100 0.216 4130
200 0.432 8270
300 0.648 1.24 × 104
400 0.865 1.65 × 104
500 1.08 2.07 × 104
600 1.30 2.48 × 104
700 1.51 2.89 × 104
800 1.73 3.31 × 104
900 1.95 3.72 × 104
1000 2.16 4.13 × 104
2000 4.32 8.27 × 104
3000 6.48 1.24 × 105
4000 8.65 1.65 × 105
5000 10.8 2.07 × 105
5580 12.1 2.31 × 105
Steel I Beam: W12 × 45 (Wide Flange 12 inch tall × 45 lbf/ft)
L = 50.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
45.0 0.237 2910
50.0 0.264 3230
60.0 0.317 3880
70.0 0.369 4520
80.0 0.422 5170
90.0 0.475 5810
100 0.528 6460
200 1.06 1.29 × 104
300 1.58 1.94 × 104
400 2.11 2.58 × 104
500 2.64 3.23 × 104
600 3.17 3.88 × 104
700 3.69 4.52 × 104
800 4.22 5.17 × 104
900 4.75 5.81 × 104
1000 5.28 6.46 × 104
2000 10.6 1.29 × 105
2290 12.1 1.48 × 105
Steel I Beam: W12 × 45 (Wide Flange 12 inch tall × 45 lbf/ft)
L = 60.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
45.0 0.492 4190
50.0 0.547 4650
60.0 0.656 5580
70.0 0.766 6510
80.0 0.875 7440
90.0 0.985 8370
100 1.09 9300
200 2.19 1.86 × 104
300 3.28 2.79 × 104
400 4.38 3.72 × 104
500 5.47 4.65 × 104
600 6.56 5.58 × 104
700 7.66 6.51 × 104
800 8.75 7.44 × 104
900 9.85 8.37 × 104
1000 10.9 9.30 × 104
1100 12.1 1.03 × 105
Steel I Beam: W12 × 45 (Wide Flange 12 inch tall × 45 lbf/ft)
L = 70.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
45.0 0.912 5700
50.0 1.01 6330
60.0 1.22 7600
70.0 1.42 8860
80.0 1.62 1.01 × 104
90.0 1.82 1.14 × 104
100 2.03 1.27 × 104
200 4.05 2.53 × 104
300 6.08 3.80 × 104
400 8.11 5.07 × 104
500 10.1 6.33 × 104
595 12.1 7.53 × 104
Steel I Beam: W12 × 45 (Wide Flange 12 inch tall × 45 lbf/ft)
L = 80.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
45.0 1.56 7440
50.0 1.73 8270
60.0 2.07 9920
70.0 2.42 1.16 × 104
80.0 2.77 1.32 × 104
90.0 3.11 1.49 × 104
100 3.46 1.65 × 104
200 6.92 3.31 × 104
300 10.4 4.96 × 104
349 12.1 5.77 × 104
Steel I Beam: W12 × 45 (Wide Flange 12 inch tall × 45 lbf/ft)
L = 90.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
45.0 2.49 9420
50.0 2.77 1.05 × 104
60.0 3.32 1.26 × 104
70.0 3.88 1.47 × 104
80.0 4.43 1.67 × 104
90.0 4.99 1.88 × 104
100 5.54 2.09 × 104
200 11.1 4.19 × 104
218 12.1 4.56 × 104
Steel I Beam: W12 × 45 (Wide Flange 12 inch tall × 45 lbf/ft)
L = 100 ft
P (lbf/ft) w_max (in) stress_max (psi)
45.0 3.80 1.16 × 104
50.0 4.22 1.29 × 104
60.0 5.07 1.55 × 104
70.0 5.91 1.81 × 104
80.0 6.75 2.07 × 104
90.0 7.60 2.33 × 104
100 8.44 2.58 × 104
143 12.1 3.69 × 104
Steel I Beam: W12 × 45 (Wide Flange 12 inch tall × 45 lbf/ft)
L = 125 ft
P (lbf/ft) w_max (in) stress_max (psi)
45.0 9.28 1.82 × 104
50.0 10.3 2.02 × 104
58.5 12.1 2.36 × 104
Additional Information
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