Load Combinations Calculator
Combine specified dead, live, snow, wind, and seismic load effects into factored ultimate limit states (ULS) design values to NBCC 2020. Enter each load effect in the same unit (kN, kN/m, or kN·m); the calculator returns each combination case and the governing (largest) value.
Unverified against a worked example — professional review recommended.The NBCC 2020 load-combination factors used here were independently verified against the code,
and this is a deterministic application of them, so build risk is low — but this calculator hasnot been checked against a published numeric worked example. Have the load combinations
reviewed by a qualified structural engineer before use.
Standard used on this page:NBCC 2020 Division B, Table 4.1.3.2.-A (Limit States Design load combinations, no crane loads).
Snow companion factor is the 2020 value 1.0S (raised from 0.5S in pre-2015 editions).
Scope: additive (1.25D) gravity combinations. Where dead load counteracts the
effect (uplift or overturning under wind or earthquake), NBCC uses a 0.9D minimum dead-load factor
instead — that reversal case is not computed here. Serviceability (SLS) deflection checks use
specified (unfactored) loads with the CSA S16 deflection limits; the SLS value below is a reference only.
This calculator provides preliminary, indicative structural calculations only, intended to
assist with initial sizing and understanding. It is not a substitute for assessment by a
qualified structural engineer, and ca.cad-steel.com accepts no responsibility for its use
in any final design.