Concrete mix designs are all slightly different but in general terms, concrete weighs 150 lbs (pounds) per 1 cubic foot.
The actual weight of the concrete is determined by its density which will increase or decrease a little depending on aggregate, water, cement, and air used to make the concrete mixture.
The individual weights of the aggregate, sand, cement, and water in a cubic foot of concrete are:
These weights total 150 pounds per cubic foot and are based on a 3000 psi concrete mix using 3/4 inch stone.
Use these weights per cubic foot of concrete as a general guide. Using different aggregates and more or less mixing water will change the weights a bit.
You can use this calculator to determine the weight of concrete per cubic foot, per cubic yard, per cubic inch, and in kilograms.
Just enter your volume, use the drop down box to determine which weight you want, and click on the calculate button.
Generally speaking, concrete weighs 4050 pounds per cubic yard.
One cubic yard of concrete is equal to twenty seven (27) cubic feet of concrete.
If you divide 4050 pounds by 27 cubic feet you get 150 pounds per cubic foot.
The individual weights of aggregate, cement, sand, and water in a yard of concrete are:
These weights are based on a concrete mix of 3000 psi concrete using 3/4" stone aggregate.
A cubic inch of concrete is pretty small but we can do the calculations based on the weight of a cubic foot of concrete.
First of all, there are 1728 cubic inches in 1 cubic foot.
If 1 cubic foot of concrete weighs 150 lbs then you divide that by 1728 to get the weight per cubic inch.
150 / 1728 = .087 pounds or 1.39 oz.
A cubic inch of concrete weighs .087 pounds or 1.39 ounces.
A cubic inch of concrete also weighs .039 kg.
Concrete weighs 2400 kg per cubic meter.
Using the weight of concrete per cubic yard and converting it to kilograms is done as follows:
1 cubic meter is equal to 1.3 cubic yards
If 1 cubic yard of concrete weighs 4050 lbs, multiply that by 1.3 to get your cubic meter weight in pounds = 5265 lbs
1 pound is equal to .453 kilograms.
5265 pounds (1 cubic meter of concrete) x .453 = 2400 kg per cubic meter of concrete. (rounded off)
The weight of concrete per square foot is going to depend on how thick the concrete slab is.
If your square foot of concrete is 6 inches thick, you have to divide 6 (inches) by 12 (1 ft.) to figure out the thickness in feet. 6 / 12 = .5 feet
You know, from the information above, a cubic foot of concrete weighs 150 pounds.
Multiply 150 pounds by .5 feet and you get 75 pounds for a square foot of concrete that's 6 inches thick.
How much does a 4" thick square foot of concrete weigh?
4 / 12 = .333 150 lbs X .333 = 49.95 pounds per sq. ft.
How much does a 16 inch square foot of concrete weigh?
16 / 12 = 1.333 150 lbs X 1.333 = 199.95 pounds per square foot.
You can use this formula to figure the weight of a square foot of concrete for any thickness.
Concrete weight per square foot varies slightly depending on the aggregates used to make the concrete, so use these figures at your discretion.
To calculate the weight of a concrete slab, you have to know the thickness of the slab.
Once you know the thickness of the slab, you can calculate the weight per square foot based on the formula above.
EXAMPLE: What is the weight of a 20' x 20' x 4" thick concrete slab?
First, convert the thickness to feet by dividing 4 by 12.
4 / 12 = .33 ft thick
Second, calculate the weight per sq. ft. by using 150 lbs per cubic foot X .33 (that equals 49.95 lbs per sq. ft.)
Third, calculate your total square feet of your concrete slab L X W = SF (20 x 20 = 400 sf)
Fourth, multiply your total sf (400) by your calculated weight per sq. ft. (49.95)
ANSWER: 400 x 49.95 = 19,980 Pounds
Another way to calculate the weight of a concrete slab is if you know the total cubic yards of the slab.
A cubic yard of concrete weighs 4050 pounds (estimated)
A 20' x 20' x 4" concrete slab figures 4.94 yards of concrete.
4050 X 4.94 = 20,007 total pounds.
Very close to the square foot formula.
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