Snow Load Calculator: Calculate Weight of Snow on Roofs & Surfaces

Our snow load calculator helps you determine the exact weight of snow accumulating on roofs, decks, and other surfaces. Whether you're a homeowner concerned about roof safety or a structural engineer calculating loads, this tool provides accurate snow weight calculations based on depth, area, and snow density.

How to Use the Snow Load Calculator

Step 1: Choose Your Unit System Select between Imperial (inches, feet, pounds) or Metric (centimeters, meters, kilograms) units based on your preference.

Step 2: Enter Snow Measurements

• Snow Depth: Measure the depth of accumulated snow
• Length: Enter the length of the surface area
• Width: Enter the width of the surface area

Step 3: Select Snow Type Choose from predefined snow densities or enter a custom value:

• Light Snow: 4.4 lb/ft� (70 kg/m�) - Fresh, powdery snow
• Medium Snow: 12.5 lb/ft� (200 kg/m�) - Settled snow
• Heavy Snow: 25 lb/ft� (400 kg/m�) - Wet, compacted snow
• Custom Density: Enter your own density value

Step 4: Get Results The calculator instantly displays the total snow load using the formula: Snow Load = Depth � Area � Density

Snow Load Calculation Formula

The snow load calculation follows this fundamental engineering formula:

1Total Snow Load = Snow Depth � Surface Area � Snow Density
2

Where:

• Snow Depth = Measured thickness of snow accumulation
• Surface Area = Length � Width of the surface
• Snow Density = Weight per unit volume (varies by snow type)

Understanding Different Snow Types

Light Snow (Fresh Powder)

• Density: 4.4 lb/ft� (70 kg/m�)
• Characteristics: Recently fallen, fluffy snow
• Common conditions: Cold temperatures, dry climate

Medium Snow (Settled)

• Density: 12.5 lb/ft� (200 kg/m�)
• Characteristics: Snow that has settled for days or weeks
• Common conditions: Average winter conditions

Heavy Snow (Wet/Compacted)

• Density: 25 lb/ft� (400 kg/m�)
• Characteristics: Wet snow, ice layers, or wind-packed snow
• Common conditions: Warm weather, rain on snow, high winds

Real-World Applications

Roof Snow Load Assessment

Use this roof snow load calculator to:

• Assess structural safety of residential roofs
• Determine when snow removal is necessary
• Calculate loads for building permits
• Plan winter maintenance schedules

Deck and Structure Safety

Calculate snow weight for:

• Outdoor decks and patios
• Carports and awnings
• Temporary structures
• Storage buildings

Construction and Engineering

Professional applications include:

• Structural load analysis
• Building design calculations
• Safety margin assessments
• Code compliance verification

Snow Load Safety Guidelines

When to Remove Snow:

• Total load exceeds structural capacity
• Visible sagging or stress signs
• Multiple snow layers with ice
• Manufacturer recommendations exceeded

Safety Considerations:

• Monitor weather forecasts for additional snowfall
• Consider dynamic loads from wind
• Account for uneven snow distribution
• Factor in roof slope and material

Frequently Asked Questions

What is a safe snow load for my roof?

Most residential roofs are designed to handle 20-30 pounds per square foot (psf). However, consult your building plans or a structural engineer for specific load ratings.

How do I measure snow depth accurately?

Use a ruler or yardstick to measure snow depth in multiple locations, then calculate the average. Measure on a level surface away from drifts or wind-blown areas.

Why does snow density matter in calculations?

Snow density varies significantly based on temperature, age, and moisture content. Light powder snow weighs much less than wet, compacted snow of the same depth.

When should I be concerned about roof snow load?

Be concerned when total calculated load approaches 20 psf, when you notice roof sagging, or when wet snow creates ice dams. Remove snow if loads exceed safe limits.

Can I use this calculator for commercial buildings?

While this tool provides accurate calculations, commercial buildings require professional structural analysis. Use results as preliminary estimates only.

What factors affect snow density?

Temperature, humidity, wind, snow age, and precipitation type all influence density. Wet snow can be 5-10 times heavier than dry powder.

How often should I check roof snow loads?

Check after each significant snowfall and monitor throughout winter storms. Pay special attention during temperature fluctuations that create ice layers.

What's the difference between ground snow load and roof snow load?

Ground snow load is measured at ground level, while roof snow load accounts for factors like wind, roof slope, and building heat that affect accumulation patterns.

Winter Safety and Maintenance

Snow Removal Best Practices

• Remove snow when loads approach design limits
• Clear drainage areas to prevent ice dams
• Use proper tools to avoid roof damage
• Consider professional removal for steep roofs

Monitoring Throughout Winter

• Track accumulated snowfall totals
• Watch for signs of structural stress
• Monitor weather forecasts for additional snow
• Inspect gutters and drainage systems

Technical Specifications

Our snow load calculator uses industry-standard density values:

• Calculations follow ASCE 7 guidelines
• Supports both Imperial and Metric units
• Real-time input validation
• Precise mathematical formulas

Conclusion

This snow load calculator provides essential safety information for winter property management. Whether calculating roof snow loads, assessing deck capacity, or planning snow removal, accurate load calculations protect both structures and occupants. Use this tool regularly throughout winter to maintain safe snow loads on all surfaces.

Remember: When in doubt about structural capacity, consult a professional engineer. This calculator provides estimates - actual load ratings depend on specific building designs and local codes.