# Snow Weight Calculator • Snow Density Chart • Snow Types

By Roof Online Staff • Last updated March 16, 2024

## Introduction

The weight of snow is a vital piece of information. Whole sections of the building code are based on knowing how much additional weight a structure will need to support due to the typical snow loads in a given region.

There is no foolproof rule of thumb regarding snow weight. To estimate snow weight accurately, you need to know the conditions under which the snow formed, and what conditions the snow has experienced since it fell.

Snow can vary in weight from a little over a pound to as much as 30 pounds per cubic foot. Fresh, dry, fluffy snow might only weigh about four pounds per cubic foot. Snow that has been sitting for a few days under normal conditions will usually weigh around 15 pounds per cubic foot.

But there are variables, and they make a big difference.

## Snow Weight Calculator

This calculator uses the values and snow types presented in the snow density table below. The values and snow types were derived from the sources listed at the bottom of the page.

The types of snow are described after the calculator.

This calculator uses the average weights for the different types of snow, but the weights in reality occur in a range. You can see the weight ranges in the snow weight table farther down the page.

Also note that very deep snow can be self-compacting, which increases the weight of a given volume and type of snow (see “Snow Depth and Snow Weight” below) and this calculator does not account for that.

Snow Weight Calculator

## Snow Weight Calculator

Select Type of Snow:
Area Length:
Area Width:
Depth of Snow:

## Types of Snow

This is a list of different types of snow (and ice) arranged from lightest to heaviest.

1. Wild Snow: Light, very dry new snow. Snow immediately after falling, in extremely cold temperatures, with no wind.
2. Ordinary New Snow: Snow immediately after falling, in below-freezing temperatures, with no wind; fresh, uncompacted snow that has a high volume of trapped air.
3. New Snow Slightly Compacted by Wind: Snow immediately after falling, in below-freezing temperatures, with some wind exposure. Less trapped air.
4. Settling Snow: Snow less than a day old that is starting to experience some wind and temperature variation.
5. Damp New Snow: Snow immediately after falling, in slightly above-freezing temperatures, with little wind exposure.
6. Sugar Snow: Snow with large grains formed when water vapor freezes onto existing snow crystals.
7. Settled Snow: Typical after more than one day in place. Snow that has experienced some temperature and wind variation.
8. Average Wind-Toughened Snow: Compacted snow after wind exposure in below-freezing temperatures.
9. Wet Snow: Dense, sticky snow in relatively warm temperatures with little wind. Good snow for making snowballs.
10. Wind-Packed Snow: Hard Wind Slab. Compacted snow after prolonged and heavy wind exposure.
11. New Firn Snow: Firn is granular, icy, highly-compacted, pre-glacial snow. Some ice present.
12. Advanced Firn Snow: A more compacted and dense form of Firn snow.
13. Thawing Firn Snow: Firn snow undergoing thawing and melting processes.
14. Slush: Advanced melting snow; a snow/water mix.
15. Ice with Air Bubbles: Cloudy ice with entrapped air bubbles.
16. Pure Ice: Ice with no entrapped air.

## What Determines Snow Density?

Snow density is a function of temperature, wind exposure, time, and the depth of the snow.

Snow density increases over time as the snow experiences more changes in temperature and wind. Warmer temperatures lead to higher (and heavier) moisture content, and this moisture may re-freeze into ice when the temperature drops.

Wind abrades snow particles, making them smaller and rounding off their edges so they have a more uniform shape. This allows them to fit together more tightly, compacting the snow, so snow will be heavier after being exposed to wind.

Snow will also be compacted by its own weight, so the deeper the snow, the denser the lower portion of the snowfall will be, and the heavier the snow will be on average per unit of volume.

## Why You Should Know How Heavy Snow Is

The weight of snow can be an important piece of information for a number of reasons.

For instance, a typical scoop of snow with a snow shovel is about 1.5 cubic feet, so there’s a good chance you’re out there lifting more than 30 lbs. over and over again while you’re clearing your driveway. It’s good to know the weight of snow.

Roof collapse due to the weight of snow exceeding the load-bearing capacity of a roof structure is a primary concern of people looking up the weight of snow. For in-depth information on how the weight of snow may affect your roof, please see the references at the bottom of this page.

### Removing Snow from a Roof

Anyone planning to remove snow from a roof should first have a look at “Falls and Other Hazards to Workers Removing Snow from Rooftops and Other Elevated Surfaces“. This safety guide was put together by OSHA and we recommend that you take a few minutes to read it.

If you’re considering trying to remove snow from your roof yourself, please see these snow rakes (on Amazon). They are designed to allow snow to be removed while you are standing on the ground. Using a ladder in the snow can be very dangerous.

Actually climbing up on a roof to remove snow is insanely dangerous and you should not try this at home.

You should never remove all of the snow from one side of a roof before moving on to the other side of the roof, especially with heavy snow loads. Doing this increases the chances that your roof’s support structure will fail, especially at the connections between the structural members.

When removing snow from a roof, you should remove a little from each side, and then a little more from each side, and so on. This way the load remains balanced, and doesn’t push on the roof structure from just one side in way it isn’t designed to handle.

Asymmetrical snow removal creates a load imbalance on your roof that can overstress and possibly break the framing connections in your roof structure. Read more here.

## About Our Snow Weight Table

The following table provides the typical weight of snow (or snow density) for snow that has formed and accumulated under various conditions.

Weights for air, ice, and liquid water are also included, as these are the three principal components of snow. The weight of snow is a product of the percentage of each of these things within a given volume of snow. (We do not account for dirt, debris, etc. when calculating the weight of snow.)

### Snow Depth and Snow Weight

Important Note: Be aware that the average density of snow will increase as the snow gets deeper, as the weight of the additional snow above will compact the snow closer to the bottom. The deeper the snow, the heavier the average weight of the snow will be per unit of volume.

As an example, if snow that is 6 inches deep has an average density of 1 pound per square foot per inch of depth, the same type of snow at 4 feet deep will typically weigh 1.5 pounds per inch per square foot.

In other words, increasing the depth of the snow from from 6 inches deep to 4 feet deep increases the average snow density by about 50%.

Here’s another example: According to NASA, “a cubic meter of freshly-fallen snow has an average mass of about 50 kilograms. Snow that has been compacted by its own weight at a depth of 3 meters can have 200 kilograms in the same volume.”

That is an increase in snow density of 300% for the bottom meter of 3-meter-deep snow.

Keep this in mind when using the table below.

## Table: Weight of Snow for Various Snow Types

All weights given in this table are approximations and real world values will vary.

Weight of Snow
Type of Snow Lbs per Inch of Depth per Square Foot
(Average)
Lbs per Cubic Foot
(lb/ft³)
(Average)
Lbs per Cubic Foot
(lb/ft³)
(Range)
Grams per Cubic Centimeter
(g/cm³)
(Range)
Kg per Cubic Meter
(kg/m³)
(Average)
Kg per Centimeter of Depth per Square Meter
(Average)
Air
(Average weight of air at sea level at freezing.)
0.007 lbs 0.08
lb/ft³
0.08
lb/ft³
0.0013
g/cm³
1.29
kg/m³
0.0129 kg
Wild Snow
(Light, very dry new snow. Snow immediately after falling, in extremely cold temperatures, with no wind.)
0.1 lbs 1.25
lb/ft³
0.62 – 1.87
lb/ft³
0.01 – 0.03
g/cm³
20
kg/m³
0.20 kg
Ordinary New Snow
(Snow immediately after falling, in below-freezing temperatures, with no wind; fresh, uncompacted snow that has a high volume of trapped air.)
0.3 lbs 3.59
lb/ft³
3.12 – 4.06
lb/ft³
0.05 – 0.065
g/cm³
57.5
kg/m³
0.58 kg
New Snow Slightly Compacted by Wind
(Snow immediately after falling, in below-freezing temperatures, with some wind exposure. Less trapped air.)
0.37 lbs 4.46
lb/ft³
3.93 – 4.99
lb/ft³
0.063 – 0.08
g/cm³
71.5
kg/m³
0.715 kg
Settling Snow
(Snow less than a day old that is starting to experience some wind and temperature variation.)
0.68 lbs 8.12
lb/ft³
4.37 – 11.86
lb/ft³
0.07 – 0.19
g/cm³
130
kg/m³
1.30 kg
Damp New Snow
(Snow immediately after falling, in slightly above-freezing temperatures, with little wind exposure.)
0.78 lbs 9.37
lb/ft³
6.24 – 12.49
lb/ft³
0.1 – 0.2
g/cm³
150
kg/m³
1.50 kg
Sugar Snow
(Snow with large grains formed when water vapor freezes onto existing snow crystals.)
1.04 lbs 12.49
lb/ft³
6.24 – 18.73
lb/ft³
0.1 – 0.3
g/cm³
200
kg/m³
2 kg
Settled Snow
(Typical after more than one day in place. Snow that has experienced some temperature and wind variation.)
1.3 lbs 15.61
lb/ft³
12.49 – 18.73
lb/ft³
0.2 – 0.3
g/cm³
250
kg/m³
2.5 kg
Average Wind-Toughened Snow
(Compacted snow after wind exposure in below-freezing temperatures.)
1.46 lbs 17.48
lb/ft³
17.48
lb/ft³
0.28
g/cm³
280
kg/m³
2.8 kg
Wet Snow
(Dense, sticky snow in relatively warm temperatures with little wind. Good snow for making snowballs.)
1.75 lbs 21
lb/ft³
17 – 25
lb/ft³
0.27 – 0.40
g/cm³
335
kg/m³
3.35 kg
Wind-Packed Snow
(Hard Wind Slab. Compacted snow after prolonged and heavy wind exposure.)
1.98 lbs 23.73
lb/ft³
21.85 – 25.6
lb/ft³
0.35 – 0.41
g/cm³
380
kg/m³
3.8 kg
New Firn Snow
(Firn is granular, icy, highly-compacted, pre-glacial snow. Some ice present.)
2.47 lbs 29.66
lb/ft³
24.97 – 34.34
lb/ft³
0.40 – 0.55
g/cm³
475
kg/m³
4.75 kg
Advanced Firn Snow 3.12 lbs 37.46
lb/ft³
34.34 – 40.58
lb/ft³
0.55 – 0.65
g/cm³
600
kg/m³
6 kg
Thawing Firn Snow 3.38 lbs 40.58
lb/ft³
37.46 – 43.70
lb/ft³
0.6 – 0.7
g/cm³
650
kg/m³
6.5 kg
Slush
(Advanced melting snow; snow/water mix.)
3.75 lbs 45
lb/ft³
35 – 55
lb/ft³
0.56 – 0.88
g/cm³
720
kg/m³
7.2 kg
Ice with Air Bubbles
(Cloudy ice.)
4.5 lbs 54
lb/ft³
51.19 – 56.81
lb/ft³
0.82 – 0.91
g/cm³
873
kg/m³
8.73 kg
Pure Ice
(Ice with no entrapped air.)
4.77 lbs 57.25
lb/ft³
57.25
lb/ft³
0.92
g/cm³
917
kg/m³
9.17 kg
Water
(At sea level just above freezing.)
5.2 lbs 62.43
lb/ft³
62.43
lb/ft³
1
g/cm³
1000
kg/m³
10 kg

## Snow Weight References

1. General: “Prevent Roof Damage from Heavy Snow and Ice” is a brief overview article produced by the Insurance Institute for Business & Home Safety.

2. General: Snow Load Safety Guide” is a useful and fairly detailed article produced by FEMA as a part of their Risk Management Series.

3. Codes: See “Section 1608 Snow Loads“ in the 2018 International Building Code for snow-load-related design considerations. Available on the UpCodes website.

4. Safety: “Falls and Other Hazards to Workers Removing Snow from Rooftops and Other Elevated Surfaces“. From OSHA. Recommended reading for anyone planning to remove snow from a roof.

5. Technical: To find the design ground snow load for a specific location, see the Hazards by Location page at the website of the Applied Technology Council.

6. Technical: “Framing: Snow Loads on Roofs” succinctly explains the interaction between pitched roof structures and snow loads. Why you shouldn’t remove all the snow from one side of a roof before the other side. From the Journal of Light Construction, 2008.

7. Technical: Design: “Building Design Considerations In Cold Climates” from the Whole Building Design Guide is definitely worth a look.

8. Technical: Design: “Minimizing the Adverse Effects of Snow and Ice on Roofs” is a design-oriented article from 2001 available at the US Army Engineer Research and Development Center website. It’s not overly technical and provides a good overview of snow and ice issues.