Span Calculator for Wood Joists and Rafters
Enhance the precision of your projects with our advanced Span Calculator, updated to reflect the 2024 NDS Supplement - Design Values for Wood Construction. This tool is designed to provide accurate maximum span calculations for a wide range of commercially available softwood and hardwood lumber, including prominent species such as Douglas Fir, Southern Pine, Hem-Fir, and Spruce-Pine-Fir. It offers specialized support for calculating ceiling joist spans, rafter snow loads, and live loads across diverse wood types, including Coast Sitka Spruce, Alaska Yellow Cedar, and Eastern White Pine. This calculator is essential for professionals striving to ensure structural integrity and compliance with rigorous engineering standards.
Results
Max Span Results
Max Span Parameters
Notes and Disclaimers
Loading Condition:
Calculated beam is assumed to be simply supported and subjected to uniform loading along its length.
Lateral Support:
The top of the beam, joist, or rafter is assumed to be supported throughout its length (through attachment to floor or roof sheathing) to prevent lateral displacement, and the ends, at points of bearing, have lateral support to prevent rotation.
Disclaimer:
While every effort has been made to insure the accuracy of the information presented, and special effort has been made to assure that the information reflects the state-of-the-art, RedX Technology nor its members assume any responsibility for any particular design prepared from this Span Calculator. Those using this Span Calculator assume all liability from its use.
Sources:
The formulas used in this tool are based on the guidelines provided by the American Wood Council's Span Calculator Help.
The design values are derived from the 2024 NDS Supplement - Design Values for Wood Construction published by the American Wood Council.