Snow Load Calculator

Estimate the snow load on your roof using ASCE 7 simplified coefficients. Enter your local ground snow load, roof dimensions, and conditions to see the design snow pressure and total weight your roof must support.

Ground Snow Load (PSF)

Roof Length (ft)

Roof Width (ft)

Roof Pitch

Exposure

Thermal Condition

Importance Factor

Roof Snow Load

20.2 PSF

Flat roof load pf = 21.0 PSF

Total Weight

22,579 lbs

11.3 tons on 1,120 sq ft

Fresh Snow Depth

13 inches

Packed: ~7 inches

Roof Pitch	Snow Load (PSF)	Total Weight
0/12 (Cs = 1)	21.0 PSF	23,520 lbs
2/12 (Cs = 1)	21.0 PSF	23,520 lbs
4/12 (Cs = 0.96)Best value	20.2 PSF	22,579 lbs
6/12 (Cs = 0.85)	17.8 PSF	19,992 lbs
8/12 (Cs = 0.7)	14.7 PSF	16,464 lbs
12/12 (Cs = 0.4)	8.4 PSF	9,408 lbs

Snow Accumulation MonitoringAt your calculated load of 20.2 PSF, that is equivalent to roughly 13 inches of fresh snow or 7 inches of packed snow. Monitor accumulation after storms and consider removing snow before it reaches these depths, especially if rain-on-snow events are expected (which dramatically increase load).

This is a simplified estimate based on ASCE 7 methods. It does not account for drift loads, sliding snow, rain-on-snow surcharges, or unbalanced loading. Always consult a licensed structural engineer and your local building department for actual design loads.