Unit Weight of Building Materials Used In Construction

What is Unit Weight?

Unit weight or specific weight of any material is its weight per unit volume that means in a unit volume, how much weight of the material can be placed.

Volume is measured in litres or cubic meters, and weight is expressed in kg or kilo Newton. Hence it is expressed in KN/m3 in the SI unit and KG/ m3 in the MKS unit system, and g/cc in the CGS unit system. 

Unit or Specific Weight = Weight / Volume = W / V

What is Density?

The density of any substance/material is its mass per unit volume, and it is expressed in  KG/ m3 or lb/m3. The symbol Rho (ρ) represents it.

Density describes the level of compactness of a substance. If the material has more density, that means it is more compact.

Density = Mass / Volume

ρ = M/V

Unit Weight of Building Materials Used In Construction

What is the difference Between Unit or Specific Weight and Density?

Unit weight of any substance is its weight per unit volume, while the density of any material is its mass per unit volume. Both terms can be used interchangeably.

To understand the difference between unit weight and the density first, we need to understand the difference between weight and mass.

Any substance or material on this planet or anywhere has some mass, and it can’t be zero, and it is measured in kg. M denotes it.

M = w/g

While weight is a force due to gravity acceleration and it is measured in newton. If there is no gravity acceleration, it may be zero. It is denoted by W.

W = m × g

Where g = acceleration due to gravity

I hope now you understood the difference between these two terms.

Why is Unit Weight Important?

The unit weight is essential for weight calculation purposes. With the help of Unit Weight, we can calculate the weight of any material.

It also helps to determine the structure’s weight, which is designed to carry the specific load so that it remains intact and within limits.

Unit weight of any material also helps to calculate the quantity of material required for particular space.

The density of any material also decides whether it will sink or float on water. Suppose the substance density is less than water’s density.

In that case, it will float, and if the substance density is more than the water’s density, it will sink into the water.

Unit Weight of Materials Used In Construction

Here we are providing the unit weight of different building materials in alphabetical order for your convenience.


1 kN/m3 = 101.9716 kg/m3 say = 100 kg/m3 (round off)

1 kg/m3 = 0.0624 lb/ft3

S.No.MaterialsUnit Weight
in Kg/m3
Unit Weight
in KN/m3
Unit Weight
in lb/ft3
1Asbestos Sheet170.171.0608
2ACC Block551 to 6005.51-6.0034.38-37.44
4Anthracite Coal134613.4683.9904
8Birch Plywood6806.842.432
9Birch Wood6706.741.808
11Brick (Red)192019.20119.81
12Brick Dust (Surkhi)101010.163.024
13Brick Jelly142014.288.608
14Brick Masonry192019.2119.808
15Cast iron720372.03449.4672
16Cement Concrete Block180018112.32
17Cement Grout1500 to 180015-1893.6-112.32
18Cement Mortar208020.8129.792
19Cement Slurry144214.4289.9808
20Cement (ordinary)144014.489.856
22Clay Soil190019118.56
24Coal Tar12001274.88
25Coarse Aggregate1680-175016.8-17.5104.83-109.2
27Conifer Plywood460 – 52046-5228.7-32.45
29Crude Oil8808.854.912
32Dry Rubble Masonry208020.8129.792
33Earth (Dry)1410-184014.1-18.487.98-114.82
34Earth (Moist)1600-200016-2099.84-124.8
35Fly Ash1120 to 150011.2-1569.88-93.6
36Fly Ash Brick Masonry2000 to 210020-21124.8-131.04
37Fly Ash Bricks1468 to 170014.68-1791.60-106.08
38Galvanized Iron Steel (0.56 mm)50.050.312
39Galvanized Iron Steel (1.63 mm)130.130.8112
41Geo Polymer Concrete240024149.76
43Glass Reinforced Concrete2000 to 210020-21124.8-131.04
44Granite Stone2400-269024-26.9149.76-167.85
46Gravel Soil200020124.8
47Green Concrete2315 to 249923.15-24.99144.45-155.93
48Gypsum Mortar12001274.88
49Gypsum Powder1410-176014.1-17.687.98-109.82
50Heavy Charcoal5305.333.072
52Igneous rocks (Felsic)270027168.48
53Igneous rocks (Mafic)300030187.2
55Larch Wood5905.936.816
56Laterite Stone1019 10.1963.58
58Light Charcoal300318.72
59Light Weight Concrete800 to 10008-1049.92-62.4
60Lime Concrete190019118.56
61Lime Mortar1600-184016-18.499.84-114.82
62Lime Stone2400 – 272024-27.2149.76-169.73
63M Sand154015.496.096
66Mangalore Tiles with Battens650.654.056
68Marble Stone262026.2163.488
69Metamorphic rocks270027168.48
70Mixed Plywood6206.238.688
73Nitric Acid (91 percent)151015.194.224
79Plain Cement Concrete240024149.76
80Plaster of Paris8818.8154.9744
82Pre-stressed Cement Concrete240024149.76
83Quarry Dust1300 to 145013-14.581.12-90.48
85Quick lime33450334.52087.28
86Rapid Hardening Cement125012.578
87Red Wood450-5104.5-5.128.08-31.82
88Reinforced Cement Concrete250025156
89Road Tar101010.163.024
91Rubble stone1600-175016-17.599.84-109.2
92Saline Water102510.2563.96
93Sal Wood9909.961.776
94Sand (Dry)1540-160015.4-1696.09-99.84
95Sand Wet1760-200017.6-20109.82-124.8
96Sandstone2250 to 240022.5-24140.4-149.76
97Sedimentary rocks260026162.24
98Shale Gas250025156
99Sisso Wood (Sheesham)78578.548.984
102Stainless Steel748074.8466.752
104Mild Steel785078.5489.84
105Sulphuric Acid (87 Percent)179017.9111.696
106Teak Wood630-7206.3-7.239.31-44.93
108WPC Board5505.534.32

Also, read

Specific gravity of Cement – Definition, Importance, Test Procedure

Soundness Test of Cement by Le-chatelier Apparatus

Bar Bending Schedule(BBS) – Importance, Advantages, Preparation

10 Best Cement Companies In India 2021

10 Best Tiles Companies In India 2021

200 + Civil Engineering Interview Questions & Answers

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