How To Calculate Steel Structure Building

Mar 28, 2026
Due to the advantages and extensive use of steel structures, engineering quantity calculation and software operation of steel structures have become one of the necessary knowledge and skills for general engineers. In order to let everyone understand steel structure calculation formulas, rules and software more quickly, the article lists and summarizes the basic knowledge of steel structure calculation. Let's take a look at it.

Steel structure calculation rules
 
1) Steel roof truss, steel mesh frame

Calculate the weight of the steel according to the size shown in the design, without deducting the weight of the holes, trimming and cutting limbs, and the weight of welding rods, rivets, bolts, etc. will not be added.

For irregular or polygonal steel plates, the area of the circumscribed regular rectangle is calculated.

The steel grid should distinguish the connection forms such as spherical joints and steel plate joints.

2) Steel bracket, steel truss 

·According to the size shown in the design, it is calculated by the weight of the steel. The weight of holes, trimmed edges, and cut limbs shall not be deducted, and the weight of welding rods, rivets, bolts, etc. shall not be added.

·Irregular or polygonal steel plate, calculated by its circumscribed rectangular area.

·The unit of measurement is t.
 
3) Steel column, steel beam

·According to the size shown in the design, it is calculated by the weight of the steel. The weight of holes, trimmed edges, and cut limbs shall not be deducted, and the weight of welding rods, rivets, bolts, etc. shall not be added.

·Irregular or polygonal steel plate, calculated by its circumscribed rectangular area.

·Including solid web columns, empty web columns, steel tube columns, steel beams and steel crane beams, etc. The unit of measurement is t.

·Corbels, etc. Attached to the steel column are incorporated into the steel column engineering quantity.

·The gusset plate, reinforcement ring, inner lining pipe, corbel, etc. on the steel pipe column are incorporated into the steel pipe column engineering quantity.

·When the design stipulates that steel brake beams, steel brake trusses and car blocks are set up, their engineering quantities should be incorporated into the steel crane beams.

4) Profiled steel floor, wall panels

Profiled steel plate floor: Calculated according to the size of the design drawing and the horizontal projected area of laying, and the area of columns, stacks and holes within 0.3 square meters is not deducted. The unit of measurement is square meters.

Profiled steel wall panel: Calculated according to the size of the design drawing and the hanging area. The area of holes within 0.3 square meters will not be deducted, and the area of corners, edges, and window sill flashing will not be calculated separately. The unit of measurement is square meters. The profiled steel plate floor slab is poured with reinforced concrete, and the concrete and reinforcement are calculated according to the relevant regulations in concrete and reinforced concrete.

5) Steel components

The general calculation rules for steel members are as follows:

Calculate the weight of the steel according to the size shown in the design. Such as steel supports, steel purlins, steel skylight frames, steel wall frames (including columns, beams and connecting rods), steel platforms, steel walkways, steel railings, steel funnels, steel brackets, sporadic steel components, etc. The weight of holes, trimmed edges and cut limbs will not be deducted, and the weight of welding rods, rivets, bolts, etc. will not be added. 

For irregular or polygonal steel plates, the area of the circumscribed rectangle is calculated. The unit of measurement is t.

6) Metal mesh

Calculate the area according to the size of the design diagram, including production, transportation, installation, painting, etc.
 
Steel structure calculation formula
 
Basic parameters of theoretical weight of steel bars

Weight per meter (Kg) = 0.00617 × diameter of steel bar (mm) × diameter of steel bar (mm), that is, the weight of steel bar is proportional to the square of the diameter. At the same time, the theoretical weight of the steel bar (Kg) ≈ 0.00785 × cross-sectional area [Π* steel bar radius (mm) * steel bar radius (mm)]

The weight of ordinary steel bars commonly used in construction projects:

Φ4=0.099Kg

Φ5=0.154Kg

Φ6=0.222Kg

Φ6.5=0.26Kg

Φ8=0.395Kg

Φ10=0.617Kg

Φ12=0.888Kg

Φ14=1.21Kg

Φ16=1.58Kg

Φ18=2.0Kg

Φ20=2.47Kg

Φ22=2.98Kg

Φ25=3.85Kg

Φ28=4.83kg

Φ30=5.549kg

Φ32=6.31kg

Φ36=7.99kg

Φ38=8.903kg

Φ40=9.87kg

Φ50=15.42kg

Calculation formula

Flat steel, steel plate, steel strip W=0.00785×width×thickness

Square steel W=0.00785×side length

Round steel, wire rod, steel wire W=0.00617×diameter

Steel pipe W=0.02466×wall thickness (outer diameter-inner diameter)

Equilateral angle steel W=0.00785×edge thickness (2 edge width-edge thickness)

Unequal angle steel W=0.00785×edge thickness (long edge width+ short edge width-edge thickness)

I-beam W=0.00785×waist thickness [height+ f (leg width-waist thickness)]

Channel steel W=0.00785×waist thickness [height+ e (leg width-waist thickness)]
 
Remark

1. The exact calculation formulas of angle steel, I-beam and channel steel are cumbersome, and the simplified table formula is used to calculate approximate values.

2. f value: 3.34 for general models and with a, 2.65 for b, and 2.26 for c.

3. e value: 3.26 for general models and those with a, 2.44 for those with b, and 2.24 for those with c.

4. All lengths are in millimeters.



Relevant Products
Prefab Modular Container Dormitory
Prefab Modular Container Dormitory

Prefab Modular Container Dormitory designed for efficient, scalable, and comfortable workforce housing. Durable steel structure, fast installation, and customizable layouts make it ideal for construction sites, mining camps, and student housing....

More
Modular Student Housing
Modular Student Housing

Modern Modular Student Housing with fast construction, flexible layouts, and durable structure. Ideal for universities, campuses, and large-scale student accommodation projects....

More
Container Office Space
Container Office Space

A container office is a mobile office that is built within a container. It is the ideal option for offices that ought to be placed at construction sites. Aside from that, it can also be used as a temporary office space...

More
40FT Expandable Container House
40FT Expandable Container House

40FT Expandable Container House with foldable design, fast installation, and spacious layout. Ideal for residential, site accommodation, and temporary housing solutions....

More
  • Send You Inquiry

  • Give You The Solution

  • Place The Order

  • Get Your Equipment

Ask for the Solution Suited Your Condition!

Tell us your need about equipmentin your industry, we will recommend the most suitable machine model for you!

Consult online customer service
Click it to get new verification code