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ASCE 7 Load Combination Calculator (LRFD and ASD)

Reviewed by the CalculatorHub team, edited by James Graham. Load combinations from ASCE 7-22 Sections 2.3 (LRFD) and 2.4 (ASD). Last verified 15 June 2026.

This calculator evaluates all primary ASCE 7-22 load combinations for LRFD (strength design) and returns each combination value along with the governing (maximum) combination. Enter the service-level loads: dead (D), live (L), roof live (Lr), snow (S), wind (W), and earthquake (E). The calculator applies the ASCE 7-22 Section 2.3.1 LRFD factors to each input and identifies which combination produces the largest total. Use the results as the factored design load for member design per AISC 360, ACI 318, or other material standards. Seismic load E should include both horizontal (QE) and vertical (0.2 SDS D) components.

Permanent dead load (structure + superimposed)
Occupancy live load per ASCE 7 Chapter 4
Roof live load (maintenance, equipment) per ASCE 7 Section 4.3
Balanced roof snow load pf (from snow load calculator)
Lateral wind force or uplift force (service level)
Seismic force from ELF or modal analysis (strength level)
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ASCE 7-22 LRFD load combinations

LC1: 1.4D
LC2: 1.2D + 1.6L + 0.5(Lr or S or R)
LC3: 1.2D + 1.6(Lr or S or R) + (L or 0.5W)
LC4: 1.2D + 1.0W + L + 0.5(Lr or S or R)
LC5: 0.9D + 1.0W
LC6: 1.2D + 1.0E + L + 0.2S
LC7: 0.9D + 1.0E

This calculator evaluates LC1, LC2 (with Lr), LC3 (with Lr and L), LC4 (with Lr), LC5, LC6, and LC7 and returns all values plus the maximum.

Load combination design notes

  • LC2 typically governs for gravity-only floor beams with significant live load. LC4 and LC5 govern for lateral systems.
  • The 0.9D terms (LC5, LC7) check overturning and uplift. For foundation design, 0.6D may be more appropriate (ASD uplift combination).
  • LC6 and LC7 apply in Seismic Design Category D, E, and F structures, where seismic forces must be combined with gravity.
  • For members subject to both gravity and lateral loads, all seven combinations should be checked; the worst case governs.

Frequently asked questions

What are the ASCE 7 LRFD load combinations?

ASCE 7-22 Section 2.3.1 lists seven basic LRFD (strength) combinations: (1) 1.4D; (2) 1.2D + 1.6L + 0.5(Lr or S or R); (3) 1.2D + 1.6(Lr or S or R) + (L or 0.5W); (4) 1.2D + 1.0W + L + 0.5(Lr or S or R); (5) 0.9D + 1.0W; (6) 1.2D + 1.0E + L + 0.2S; (7) 0.9D + 1.0E.

What are the ASCE 7 ASD load combinations?

ASCE 7-22 Section 2.4.1 lists eight ASD (allowable stress) combinations. Key ones: D; D+L; D+Lr (or S or R); D+0.75L+0.75(Lr or S or R); D+0.6W (or 0.7E); 0.6D+0.6W. ASD combinations use service (unfactored) loads with lower allowable stresses.

When do I use LRFD versus ASD?

LRFD is the more modern reliability-based approach and is required or preferred by most current material standards (AISC 360, ACI 318). ASD is still permitted and used widely for timber (NDS) and some older steel practice. AISC 360 permits either method.

What does the 0.9D term in ASCE 7 combo 5 mean?

The 0.9D + 1.0W combination (LRFD) checks for situations where wind uplift may overcome gravity dead load. The 0.9 factor reduces dead load to its probable minimum value when acting in an unfavourable direction with wind. This combination often governs for roof uplift and overturning.

How do I include earthquake load E in the combination?

In ASCE 7, E = rho*QE + 0.2*SDS*D for horizontal seismic effects, where rho is the redundancy factor, QE is the seismic force effect from analysis, and the 0.2*SDS*D term accounts for vertical seismic acceleration. Substitute this expanded E into combinations 6 and 7.

Official sources

Reviewed by the CalculatorHub team, edited by James Graham, 15 June 2026. See our methodology.