I Beam Load Capacity Calculator

The SkyCiv I beam load capacity calculator is a free tool to help structural engineers calculate the capacity (or strength) of an I beam, as defined by the AISC 360 Steel Design Standard. In designing a steel I beam member, determining how much strength or capacity it has is an important step. This easy-to-use tool let you perform such calculation within a few seconds thanks to easy input and output.

The calculations are based on bending, shear, axial and tension strength, so you can determine the beam size for withstanding a particular design force. These are based on the relevant AISC 360 design clause, to ensure the proper design guidelines are followed. These clauses are clearly labelled in the design report under the full version.

The tool also features design load input, so your report can clearly display the PASS/FAIL criteria of the design. For instance, if you input a bending design force of 2kip-ft and the i beam capacity tool calculates the max strength is 4kip-ft, the tool will show a 50% utility ratio for that check. These are clearly displayed on the output panel on the right side, and also on the design report if the user is using the full version.

The SkyCiv I Beam Load Capacity Calculator has an user-friendly interface that makes it simple to enter the measurements and material type of your I beam, including its length, breadth, and height. Once that is done, the calculator will do the rest of the load capacity calculation job for you.

I Beam Design Software

  • Design to AISC 360, CSA S16-14 and AS 4100:2020

  • Tension, Compression, Shear and Bending Checks

  • Integrated with the SkyCiv Section Database

  • Full Calculation Reporting

  • Built by Engineers

  • Instant Access

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About this AISC 360 Beam Capacity Calculator

What is I Beam Capacity?

I-beam capacity refers to the maximum weight or load that an I-beam can safely support without suffering permanent deformation or failure. This capacity is dependent on various factors such as the size and material of the I-beam, the span length, the type of load (point load or uniform load), and the manner in which the load is applied.

It's important to determine the load capacity of I-beams in construction projects to ensure the stability and safety of the structure. Overloading an I-beam beyond its capacity can lead to dangerous deformations or even complete failure, which can cause serious damage or harm to people and property.

That's why it's essential to accurately calculate the I-beam capacity using tools like load capacity calculators or engineering design software, such as the SkyCiv Member Design Module. These tools over a quick and accurate calculation to help you design faster and more effectively.

What determines the capacity of a beam?

The capacity of a beam is determined by several factors, including:

  • Material: The strength and type of material used to construct the beam play a major role in determining its capacity. Materials like steel and concrete have high strength-to-weight ratios and are commonly used in beam construction due to their durability and load-bearing capabilities.
  • Cross-sectional Dimensions: The width, height, and shape of the beam cross-section also play a role in its capacity. A wider and taller beam will generally have a higher capacity than a narrower, shorter one of the same material.
  • Span Length: The span length of a beam, or the distance between its supports, can also affect its capacity. As the span length increases, the beam will have to support more weight, so its capacity must be designed accordingly. The above tool can be used as a steel I beam span calculator, since the span is an input it can be adjusted and changed to work out the different capacities from each span.
  • Load Type: The type of load applied to a beam can also impact its capacity. A point load, which is a concentrated load applied at a single point, is more challenging for a beam to support than a uniform load, which is evenly distributed along the length of the beam.
  • Load Application: The manner in which the load is applied to the beam can also play a role in its capacity. For example, a beam that is loaded from the top will have a different capacity than a beam that is loaded from the bottom.

These are the key factors that determine the capacity of a beam. Understanding and considering these factors is crucial for ensuring the safety and stability of a structure.

What standard is used to determine the capacity of a section

The American Institute of Steel Construction (AISC) Steel Design Code provides design specifications and guidelines for the design and construction of steel structures, including beams, columns and even connections. SkyCiv uses AISC 360 Steel Design as well as a range of other design standards in its analysis and design software. It also forms the basis of the calculation used in this i beam capacity tool, as the clauses and equations of this design standard are referenced and used in the calculations.

The AISC design standard has two main design methods for calculating the capacity of a beam; including Allowable Stress Design (ASD) as well as Load and Factor Resistance Design (LRFD). These methods provide different approaches for calculating the capacity of a beam based on factors such as the type of load, material properties, and section properties. We cover the difference with these two standards in detail in this article: The difference between LRFD and ASD (includes a video).

LRFD method will take into account uncertainties in loads by factoring up loads and take into account uncertainties in materials by factoring down material strengths. On the other hand the ASD method will take into account uncertainties by using a single factor of safety that accounts for all uncertainties with the design. Neither method is necessarily more conservative than the other and will depend on the safety factors used in design. It is therefore important to follow the appropriate design method based on the code and project requirements. Our I beam load calculator offers both options for LRFD and ASD methodologies to provide flexibility to engineers.

CSA S16-14 Steel Beam Calculator

The SkyCiv I beam capacity calculator also includes support for the Canadian Standards Association (CSA) standard S16-14 Design of Steel Structures. The calculator can design for the compressive resistance, flexural resistance and shear resistance of different cross sections. This includes support for the Canadian Institute of Steel Construction (CISC) Wide Flange section library. To access this version of the calculator use the Flag Icon dropdown menu at the top of the input panel. We also offer AS 4100 Steel Member Design Software for Australian users.

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About SkyCiv

SkyCiv offers a wide range of Cloud Structural Analysis and Design Software for engineers. As a constantly evolving tech company, we're committed to innovating and challenging existing workflows to save engineers time in their work processes and designs.


1. What does this Beam Capacity Load Calculator do?

This calculator will calculate the capacity of an I beam section based on AISC 360 Design Standards. The calculations are based on the dimensions and member length entered by the user. As an optional input, users can also specify design loads. These design loads are then compared to the section capacity to provide an overall utility ratio.

2. What is a Beam Load Capacity?

The Beam Load Capacity (or simply section capacity) is the amount of load that a section can withstand, based on a particular standard. It is also known as strength - i.e. how much strength does this section have.

These are often calculated by the guidelines specified by a particular design standard - in this example AISC 360. There are typically capacities for different types of loads. For instance, a section might have a 10kip Shear Y capacity (strong axis) and a 2kip capacity for shear in X (weak axis). Note that the capacity in Y is much higher than X, this is because the section is designed in a way that it can take more force in its strong axis.

There are also capacities for compression, tension and bending moment forces.

3. What do the green/red utility ratios represent?

This is known as the member's Utility and represents how much of the capacity is being utilized.

For instance, if a member has a 22kip capacity, it means it is capable of taking a 22kip design load. If the applied load to that member is 10kip (based on live loads, dead loads etc..) then the overall utility is around 45%. This number is calculated by:

Design Load / Capacity = 10/22 = 0.455

i.e. the section is using 45.5% of it's overall strength

4. What other steel designs does SkyCiv offer?

With the SkyCiv Platform, you can also design the following steel elements:

  • AISI Cold Formed Steel
  • AISC Connection Design
  • Integrated Design Checks with Frame and Beam analysis software
  • Base Plate Design (AISC)

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