Accurate roof snow load calculations for USA regions. ASCE 7 compliant tool for engineers, contractors & homeowners.
Calculate Snow LoadEvery year the same fear hits the moment the first heavy flakes start falling: "Is my roof going to hold, or am I one storm away from a $50,000 repair bill?" If you live anywhere that gets real snow—Colorado, New York, Minnesota, Vermont, Alaska, the Rockies, the Himalayas, Himachal, Uttarakhand, Kashmir, or even the higher hills of Northeast India—you can't just hope for the best. You need hard numbers.
That's exactly why thousands of homeowners, builders, and engineers use our snow load calculator every single day. It's 100% free, takes less than 45 seconds, and gives you code-compliant results you can actually trust.
We use the brand-new ASCE 7-22 ground snow load maps released in 2024. Many free tools online are still running 2010 or 2016 data. That can be off by 20–40% in places like Lake Tahoe, Buffalo, or Shimla.
Enter 90210 or 12901 and it pulls the exact Pg value for your town. No more guessing from blurry zone maps.
From Manali to Montreal, Oslo to Otaru (Japan), our database has 40,000+ locations and growing.
See a 3D diagram of exactly where the dangerous drifts will pile up on your roof. Most calculators completely ignore drifting — the #1 cause of collapses.
Instant results. Save or print a professional PDF report with one click.
Over 7 feet of lake-effect snow in 4 days. Hundreds of flat-roof gyms and warehouses collapsed. The ones that survived? Owners who used a snow load calculator by zip code and reinforced early.
Heavy snow + rain-on-snow loads were a major contributing factor. Locals now use our India-specific IS 875 calculator before any new construction.
Added solar panels without checking drift loads. First big storm → 9-foot drift behind the panels → roof caved in. Insurance denied the claim because it was "poor design."
Don't let this be you.
That's literally it. Easier than checking the weather.
Quick rule of thumb (fresh powder vs packed wet snow):
Most residential roofs are designed for 20–50 psf total snow load. Do the math.
One heavy storm is all it takes to turn "I think it'll be fine" into "I should've checked."
Use the most trusted free snow load calculator by zip code right now — it's literally 30 seconds that could save you tens of thousands of dollars. ➜ Open the Snow Load Calculator (100% Free) ➜ Or bookmark this page and come back the next time the forecast says “bomb cyclone.” Your roof will thank you.
While our calculator is excellent for preliminary estimates, you should consult a structural engineer for:
Proper maintenance can help your roof handle snow loads effectively:
Our calculator is based on established engineering standards:
Our calculator follows ASCE 7 standards, which is the recognized method for snow load calculations in the United States. While it provides reliable estimates for preliminary design, it should not replace a detailed structural analysis by a licensed professional engineer for critical applications. The accuracy depends on the correctness of the input values and how well your specific situation matches the standard assumptions in ASCE 7.
Ground snow load is the weight of snow on the ground, specific to geographic locations based on historical weather data. Roof snow load is the actual design load that a roof must support, which is typically less than ground snow load due to factors like wind exposure, roof slope, and thermal conditions. The conversion from ground to roof snow load involves several reduction factors that account for how snow behaves differently on roofs compared to the ground.
Roof slope significantly impacts snow accumulation. Flat roofs (slope ≤ 5°) tend to accumulate the most snow, as there's little tendency for snow to slide off. As roof slope increases, snow is more likely to slide off, reducing the design snow load. For example, a steeply pitched roof (over 45°) may only need to be designed for 30% of the flat roof snow load. However, sliding snow can create other issues like ice dams or dangerous accumulations at roof edges, which may need separate consideration in the design.
You should consult a structural engineer for:
Ground snow load values can be found in several places:
Many municipalities have amendments to the standard ASCE 7 values based on local experience and microclimate conditions, so always check with your local building department for the most accurate information.
Yes, climate change is altering snowfall patterns in many regions, which impacts snow load calculations in several ways:
When designing new structures or evaluating existing ones, consider using slightly conservative estimates, especially in regions where climate models predict increased winter precipitation. Some engineers are adding climate change factors to their calculations to account for these uncertainties.