Truss Load Calculator
Plan your structural engineering project with our free truss load calculator. Get precise measurements, material lists, and budgets.
Formula
w = (DL + LL) * spacing | Reaction = wL/2 | Panel Load = w * panel length
The line load on a truss equals the sum of dead and live surface loads multiplied by the truss spacing. Each support reaction equals half the total load for a simply supported truss with uniform loading. Panel point loads equal the line load times the panel length. Maximum chord forces are estimated using the method of sections at midspan.
Worked Examples
Example 1: Roof Truss with Uniform Load
Problem: Calculate loads for a 12m span truss, 3m height, 1.2m spacing, with 0.5 kPa dead load and 1.0 kPa live load, 6 panels.
Solution: UDL on truss = (0.5 + 1.0) * 1.2 = 1.80 kN/m\nTotal load = 1.80 * 12 = 21.60 kN\nReaction = 21.60 / 2 = 10.80 kN\nPanel load = 1.80 * 2.0 = 3.60 kN\nMax top chord = -10.80 * 3 / 3 = -10.80 kN (compression)
Result: Reactions = 10.80 kN each, panel point load = 3.60 kN
Example 2: Long Span Industrial Truss
Problem: A 24m span truss with 6m height, 2.0m spacing, DL = 0.8 kPa, LL = 1.5 kPa, 8 panels.
Solution: UDL = (0.8 + 1.5) * 2.0 = 4.60 kN/m\nTotal = 4.60 * 24 = 110.40 kN\nReaction = 55.20 kN\nPanel length = 3.0m, Panel load = 13.80 kN
Result: Reactions = 55.20 kN, max chord force approx 55.20 kN
Frequently Asked Questions
What is a truss and how does it carry load?
A truss is a structural framework made of triangular units connected at joints (nodes). Each member carries only axial force, either tension or compression, with no bending. The top chord resists compression from bending, the bottom chord resists tension, and the diagonal web members transfer shear between the chords. This efficient load path makes trusses ideal for spanning long distances with minimal material compared to solid beams.
How do you determine the loads on a roof truss?
Roof truss loads include dead load (self-weight of roofing, insulation, ceiling), live load (maintenance access, typically 1.0 kPa), snow load (based on ground snow load and roof geometry), and wind load (which can be uplift or downward pressure). These surface loads are converted to line loads on the truss by multiplying by the truss spacing. Point loads at panel points are then calculated by multiplying the line load by the panel length.
How do I calculate the load-bearing capacity of a beam?
Beam capacity depends on material, cross-section dimensions, span length, and support conditions. For a simple rectangular wood beam, bending strength = (F_b x b x d^2) / 6, where F_b is allowable stress, b is width, and d is depth. Always consult a structural engineer for critical applications.
What formula does Truss Load Calculator use?
The formula used is described in the Formula section on this page. It is based on widely accepted standards in the relevant field. If you need a specific reference or citation, the References section provides links to authoritative sources.
Can I use Truss Load Calculator on a mobile device?
Yes. All calculators on NovaCalculator are fully responsive and work on smartphones, tablets, and desktops. The layout adapts automatically to your screen size.
Can I share or bookmark my calculation?
You can bookmark the calculator page in your browser. Many calculators also display a shareable result summary you can copy. The page URL stays the same so returning to it will bring you back to the same tool.