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Glossary » Beams » Simply Supported » Uniformly Distributed Load » Two Equal Spans » Wide Flange Steel I Beam » W18 × 40
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 and the maximum normal stress 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 = 612 in4) for the W18 × 40 Wide Flange Steel I Beam and the typical Young's modulus (E = 3.046 × 107 psi) of steels. Note that the typical yielding stress 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.

 Steel I Beam: W18 × 40 (Wide Flange 18 inch tall × 40 lbf/ft) L = 3.00 ft (lbf/ft) (in) (psi) 40.0 1.56 × 10-6 7.90 50.0 1.96 × 10-6 9.87 60.0 2.35 × 10-6 11.8 70.0 2.74 × 10-6 13.8 80.0 3.13 × 10-6 15.8 90.0 3.52 × 10-6 17.8 100 3.91 × 10-6 19.7 200 7.82 × 10-6 39.5 300 1.17 × 10-5 59.2 400 1.56 × 10-5 79.0 500 1.96 × 10-5 98.7 600 2.35 × 10-5 118 700 2.74 × 10-5 138 800 3.13 × 10-5 158 900 3.52 × 10-5 178 1000 3.91 × 10-5 197 2000 7.82 × 10-5 395 3000 1.17 × 10-4 592 4000 1.56 × 10-4 790 5000 1.96 × 10-4 987 6000 2.35 × 10-4 1180 7000 2.74 × 10-4 1380 8000 3.13 × 10-4 1580 9000 3.52 × 10-4 1780 1.00 × 104 3.91 × 10-4 1970 2.00 × 104 7.82 × 10-4 3950 3.00 × 104 0.00117 5920 4.00 × 104 0.00156 7900 5.00 × 104 0.00196 9870 6.00 × 104 0.00235 1.18 × 104 7.00 × 104 0.00274 1.38 × 104 8.00 × 104 0.00313 1.58 × 104 9.00 × 104 0.00352 1.78 × 104 1.00 × 105 0.00391 1.97 × 104 2.00 × 105 0.00782 3.95 × 104 3.00 × 105 0.0117 5.92 × 104 4.00 × 105 0.0156 7.90 × 104 5.00 × 105 0.0196 9.87 × 104 6.00 × 105 0.0235 1.18 × 105 7.00 × 105 0.0274 1.38 × 105 8.00 × 105 0.0313 1.58 × 105 9.00 × 105 0.0352 1.78 × 105 1.00 × 106 0.0391 1.97 × 105 1.50 × 106 0.0588 2.97 × 105
 Steel I Beam: W18 × 40 (Wide Flange 18 inch tall × 40 lbf/ft) L = 5.00 ft (lbf/ft) (in) (psi) 40.0 1.21 × 10-5 21.9 50.0 1.51 × 10-5 27.4 60.0 1.81 × 10-5 32.9 70.0 2.11 × 10-5 38.4 80.0 2.41 × 10-5 43.9 90.0 2.72 × 10-5 49.4 100 3.02 × 10-5 54.8 200 6.04 × 10-5 110 300 9.05 × 10-5 165 400 1.21 × 10-4 219 500 1.51 × 10-4 274 600 1.81 × 10-4 329 700 2.11 × 10-4 384 800 2.41 × 10-4 439 900 2.72 × 10-4 494 1000 3.02 × 10-4 548 2000 6.04 × 10-4 1100 3000 9.05 × 10-4 1650 4000 0.00121 2190 5000 0.00151 2740 6000 0.00181 3290 7000 0.00211 3840 8000 0.00241 4390 9000 0.00272 4940 1.00 × 104 0.00302 5480 2.00 × 104 0.00604 1.10 × 104 3.00 × 104 0.00905 1.65 × 104 4.00 × 104 0.0121 2.19 × 104 5.00 × 104 0.0151 2.74 × 104 6.00 × 104 0.0181 3.29 × 104 7.00 × 104 0.0211 3.84 × 104 8.00 × 104 0.0241 4.39 × 104 9.00 × 104 0.0272 4.94 × 104 1.00 × 105 0.0302 5.48 × 104 2.00 × 105 0.0604 1.10 × 105 3.00 × 105 0.0905 1.65 × 105 4.00 × 105 0.121 2.19 × 105 5.00 × 105 0.151 2.74 × 105 5.42 × 105 0.163 2.97 × 105
 Steel I Beam: W18 × 40 (Wide Flange 18 inch tall × 40 lbf/ft) L = 10.0 ft (lbf/ft) (in) (psi) 40.0 1.93 × 10-4 87.7 50.0 2.41 × 10-4 110 60.0 2.90 × 10-4 132 70.0 3.38 × 10-4 154 80.0 3.86 × 10-4 175 90.0 4.35 × 10-4 197 100 4.83 × 10-4 219 200 9.66 × 10-4 439 300 0.00145 658 400 0.00193 877 500 0.00241 1100 600 0.00290 1320 700 0.00338 1540 800 0.00386 1750 900 0.00435 1970 1000 0.00483 2190 2000 0.00966 4390 3000 0.0145 6580 4000 0.0193 8770 5000 0.0241 1.10 × 104 6000 0.0290 1.32 × 104 7000 0.0338 1.54 × 104 8000 0.0386 1.75 × 104 9000 0.0435 1.97 × 104 1.00 × 104 0.0483 2.19 × 104 2.00 × 104 0.0966 4.39 × 104 3.00 × 104 0.145 6.58 × 104 4.00 × 104 0.193 8.77 × 104 5.00 × 104 0.241 1.10 × 105 6.00 × 104 0.290 1.32 × 105 7.00 × 104 0.338 1.54 × 105 8.00 × 104 0.386 1.75 × 105 9.00 × 104 0.435 1.97 × 105 1.00 × 105 0.483 2.19 × 105 1.35 × 105 0.654 2.97 × 105
 Steel I Beam: W18 × 40 (Wide Flange 18 inch tall × 40 lbf/ft) L = 15.0 ft (lbf/ft) (in) (psi) 40.0 9.78 × 10-4 197 50.0 0.00122 247 60.0 0.00147 296 70.0 0.00171 345 80.0 0.00196 395 90.0 0.00220 444 100 0.00244 494 200 0.00489 987 300 0.00733 1480 400 0.00978 1970 500 0.0122 2470 600 0.0147 2960 700 0.0171 3450 800 0.0196 3950 900 0.0220 4440 1000 0.0244 4940 2000 0.0489 9870 3000 0.0733 1.48 × 104 4000 0.0978 1.97 × 104 5000 0.122 2.47 × 104 6000 0.147 2.96 × 104 7000 0.171 3.45 × 104 8000 0.196 3.95 × 104 9000 0.220 4.44 × 104 1.00 × 104 0.244 4.94 × 104 2.00 × 104 0.489 9.87 × 104 3.00 × 104 0.733 1.48 × 105 4.00 × 104 0.978 1.97 × 105 5.00 × 104 1.22 2.47 × 105 6.00 × 104 1.47 2.96 × 105 6.02 × 104 1.47 2.97 × 105
 Steel I Beam: W18 × 40 (Wide Flange 18 inch tall × 40 lbf/ft) L = 20.0 ft (lbf/ft) (in) (psi) 40.0 0.00309 351 50.0 0.00386 439 60.0 0.00464 526 70.0 0.00541 614 80.0 0.00618 702 90.0 0.00695 790 100 0.00773 877 200 0.0155 1750 300 0.0232 2630 400 0.0309 3510 500 0.0386 4390 600 0.0464 5260 700 0.0541 6140 800 0.0618 7020 900 0.0695 7900 1000 0.0773 8770 2000 0.155 1.75 × 104 3000 0.232 2.63 × 104 4000 0.309 3.51 × 104 5000 0.386 4.39 × 104 6000 0.464 5.26 × 104 7000 0.541 6.14 × 104 8000 0.618 7.02 × 104 9000 0.695 7.90 × 104 1.00 × 104 0.773 8.77 × 104 2.00 × 104 1.55 1.75 × 105 3.00 × 104 2.32 2.63 × 105 3.39 × 104 2.62 2.97 × 105
 Steel I Beam: W18 × 40 (Wide Flange 18 inch tall × 40 lbf/ft) L = 25.0 ft (lbf/ft) (in) (psi) 40.0 0.00754 548 50.0 0.00943 686 60.0 0.0113 823 70.0 0.0132 960 80.0 0.0151 1100 90.0 0.0170 1230 100 0.0189 1370 200 0.0377 2740 300 0.0566 4110 400 0.0754 5480 500 0.0943 6860 600 0.113 8230 700 0.132 9600 800 0.151 1.10 × 104 900 0.170 1.23 × 104 1000 0.189 1.37 × 104 2000 0.377 2.74 × 104 3000 0.566 4.11 × 104 4000 0.754 5.48 × 104 5000 0.943 6.86 × 104 6000 1.13 8.23 × 104 7000 1.32 9.60 × 104 8000 1.51 1.10 × 105 9000 1.70 1.23 × 105 1.00 × 104 1.89 1.37 × 105 2.00 × 104 3.77 2.74 × 105 2.17 × 104 4.09 2.97 × 105
 Steel I Beam: W18 × 40 (Wide Flange 18 inch tall × 40 lbf/ft) L = 30.0 ft (lbf/ft) (in) (psi) 40.0 0.0156 790 50.0 0.0196 987 60.0 0.0235 1180 70.0 0.0274 1380 80.0 0.0313 1580 90.0 0.0352 1780 100 0.0391 1970 200 0.0782 3950 300 0.117 5920 400 0.156 7900 500 0.196 9870 600 0.235 1.18 × 104 700 0.274 1.38 × 104 800 0.313 1.58 × 104 900 0.352 1.78 × 104 1000 0.391 1.97 × 104 2000 0.782 3.95 × 104 3000 1.17 5.92 × 104 4000 1.56 7.90 × 104 5000 1.96 9.87 × 104 6000 2.35 1.18 × 105 7000 2.74 1.38 × 105 8000 3.13 1.58 × 105 9000 3.52 1.78 × 105 1.00 × 104 3.91 1.97 × 105 1.50 × 104 5.88 2.97 × 105
 Steel I Beam: W18 × 40 (Wide Flange 18 inch tall × 40 lbf/ft) L = 40.0 ft (lbf/ft) (in) (psi) 40.0 0.0494 1400 50.0 0.0618 1750 60.0 0.0742 2110 70.0 0.0865 2460 80.0 0.0989 2810 90.0 0.111 3160 100 0.124 3510 200 0.247 7020 300 0.371 1.05 × 104 400 0.494 1.40 × 104 500 0.618 1.75 × 104 600 0.742 2.11 × 104 700 0.865 2.46 × 104 800 0.989 2.81 × 104 900 1.11 3.16 × 104 1000 1.24 3.51 × 104 2000 2.47 7.02 × 104 3000 3.71 1.05 × 105 4000 4.94 1.40 × 105 5000 6.18 1.75 × 105 6000 7.42 2.11 × 105 7000 8.65 2.46 × 105 8000 9.89 2.81 × 105 8460 10.5 2.97 × 105
 Steel I Beam: W18 × 40 (Wide Flange 18 inch tall × 40 lbf/ft) L = 50.0 ft (lbf/ft) (in) (psi) 40.0 0.121 2190 50.0 0.151 2740 60.0 0.181 3290 70.0 0.211 3840 80.0 0.241 4390 90.0 0.272 4940 100 0.302 5480 200 0.604 1.10 × 104 300 0.905 1.65 × 104 400 1.21 2.19 × 104 500 1.51 2.74 × 104 600 1.81 3.29 × 104 700 2.11 3.84 × 104 800 2.41 4.39 × 104 900 2.72 4.94 × 104 1000 3.02 5.48 × 104 2000 6.04 1.10 × 105 3000 9.05 1.65 × 105 4000 12.1 2.19 × 105 5000 15.1 2.74 × 105 5420 16.3 2.97 × 105
 Steel I Beam: W18 × 40 (Wide Flange 18 inch tall × 40 lbf/ft) L = 60.0 ft (lbf/ft) (in) (psi) 40.0 0.250 3160 50.0 0.313 3950 60.0 0.375 4740 70.0 0.438 5530 80.0 0.501 6320 90.0 0.563 7110 100 0.626 7900 200 1.25 1.58 × 104 300 1.88 2.37 × 104 400 2.50 3.16 × 104 500 3.13 3.95 × 104 600 3.75 4.74 × 104 700 4.38 5.53 × 104 800 5.01 6.32 × 104 900 5.63 7.11 × 104 1000 6.26 7.90 × 104 2000 12.5 1.58 × 105 2860 17.9 2.26 × 105
 Steel I Beam: W18 × 40 (Wide Flange 18 inch tall × 40 lbf/ft) L = 70.0 ft (lbf/ft) (in) (psi) 40.0 0.464 4300 50.0 0.580 5370 60.0 0.696 6450 70.0 0.811 7520 80.0 0.927 8600 90.0 1.04 9670 100 1.16 1.07 × 104 200 2.32 2.15 × 104 300 3.48 3.22 × 104 400 4.64 4.30 × 104 500 5.80 5.37 × 104 600 6.96 6.45 × 104 700 8.11 7.52 × 104 800 9.27 8.60 × 104 900 10.4 9.67 × 104 1000 11.6 1.07 × 105 1540 17.9 1.66 × 105
 Steel I Beam: W18 × 40 (Wide Flange 18 inch tall × 40 lbf/ft) L = 80.0 ft (lbf/ft) (in) (psi) 40.0 0.791 5620 50.0 0.989 7020 60.0 1.19 8420 70.0 1.38 9830 80.0 1.58 1.12 × 104 90.0 1.78 1.26 × 104 100 1.98 1.40 × 104 200 3.96 2.81 × 104 300 5.93 4.21 × 104 400 7.91 5.62 × 104 500 9.89 7.02 × 104 600 11.9 8.42 × 104 700 13.8 9.83 × 104 800 15.8 1.12 × 105 900 17.8 1.26 × 105 905 17.9 1.27 × 105
 Steel I Beam: W18 × 40 (Wide Flange 18 inch tall × 40 lbf/ft) L = 90.0 ft (lbf/ft) (in) (psi) 40.0 1.27 7110 50.0 1.58 8880 60.0 1.90 1.07 × 104 70.0 2.22 1.24 × 104 80.0 2.53 1.42 × 104 90.0 2.85 1.60 × 104 100 3.17 1.78 × 104 200 6.34 3.55 × 104 300 9.50 5.33 × 104 400 12.7 7.11 × 104 500 15.8 8.88 × 104 565 17.9 1.00 × 105
 Steel I Beam: W18 × 40 (Wide Flange 18 inch tall × 40 lbf/ft) L = 100 ft (lbf/ft) (in) (psi) 40.0 1.93 8770 50.0 2.41 1.10 × 104 60.0 2.90 1.32 × 104 70.0 3.38 1.54 × 104 80.0 3.86 1.75 × 104 90.0 4.35 1.97 × 104 100 4.83 2.19 × 104 200 9.66 4.39 × 104 300 14.5 6.58 × 104 371 17.9 8.13 × 104
 Steel I Beam: W18 × 40 (Wide Flange 18 inch tall × 40 lbf/ft) L = 125 ft (lbf/ft) (in) (psi) 40.0 4.72 1.37 × 104 50.0 5.89 1.71 × 104 60.0 7.07 2.06 × 104 70.0 8.25 2.40 × 104 80.0 9.43 2.74 × 104 90.0 10.6 3.08 × 104 100 11.8 3.43 × 104 152 17.9 5.20 × 104
 Steel I Beam: W18 × 40 (Wide Flange 18 inch tall × 40 lbf/ft) L = 150 ft (lbf/ft) (in) (psi) 40.0 9.78 1.97 × 104 50.0 12.2 2.47 × 104 60.0 14.7 2.96 × 104 70.0 17.1 3.45 × 104 73.2 17.9 3.61 × 104