structural steel calculations

Steel beam sizes

structural steel calculations

Steel has a high strength-to-weight ratio, meaning less steel is required in a beam than if other materials used, which makes it a sustainable and cost-effective choice. Steel is capable of withstanding high loads with minimum deflection, which prevents movement and cracking of brittle finishes such as masonry and plaster. Steel I-beams are often used in modern construction, because they are smaller and less wasteful than their wooden counterparts. Making sure that you use the right size of steel beam for your project is essential, and there are different factors that need to be considered when calculating beam size.

Steel beam size table

Below there is a table of commonly used steel beam sizes in the UK on small projects:

DimensionsDepth (mm)Width (mm)Weight per metre (kg/m)
152x89x16 UB152.488.716
178x102x19 UB177.8101.219
152x152x23 UC152.4152.923
152x152x30 UC157.6152.930
203x102x23 UB203.2101.823.1
203x133x25 UB203.2133.225.1
203x133x30 UB206.8133.930
203x203x46 UC203.2203.646.1
203x203x52 UC206.2204.352
254x146x31 UB251.4146.131.1
254x146x37 UB256146.437
254x146x43 UB259.6147.343

The benefit of steel beams is that they are manufactured to exact sizes, shapes and strengths. There are of course dozens of steel beam sizes available. So, this table is just to be used as a guide on small projects. These sizes are stocked by most steel fabricators.