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# Concrete Calculator

## Calculate The Amount Of Cocrete Needed For Walls, Slabs and More

T-One Concrete Calculator, Calculate the volume (cubic feet, cubic yards, and cubic meters) of concrete you will need for your walls, columns, steps, slabs, and footings by using this concrete calculator. If you’d prefer to use a different ready-mix concrete density, you can change the calculator’s default setting. You may also like the brick calculator. Sand Calculator and Gravel Calculator We also have buyer’s guides for builders’ sand and river sand.

Use this concrete calculator to figure out how much concrete you will need for your walls, columns, steps, slabs, footings, etc. in terms of volume (cubic feet, cubic yards, or cubic meters), weight, or number of bags. By default, the calculator uses a standard ready-mix concrete density, but you can also make your own.

Concrete Calculator

### How to use a concrete calculator: the concrete basics

Before you use a concrete calculator, it helps to know what concrete is. This will help you make estimates that are as close to reality as possible. Concrete is a mixed material that is used for all kinds of building projects, especially ones that need a lot of compressive strength. It is made up of fine and coarse aggregates that are held together by a fluid cement paste that hardens over time. It usually takes about a week to reach over 50% of its final strength and a couple of weeks to reach 95% of it. Depending on the weather and other factors, it could take a few years for a place to feel like home.

Most types of construction concrete, like Portland cement concrete and calcium aluminate cement, are made from lime. The only exception is building roads, since bitumen is used as the cement in asphalt concrete. Concretes made from polymers aren’t used very often. Most concrete is mixed with reinforcing materials, like rebar, that give it tensile strength that concrete doesn’t have on its own. This makes reinforced concrete.

Density can vary a lot between different kinds of concrete, which is an important part of figuring out how much concrete you need. For example, Portland cement concrete holds water, but “Pervious concrete” lets water pass through, so you don’t need storm drains. The density of these two kinds of concret would be very different. For accurate results, you can tell our concrete calculator how dense you want your concrete to be.

### How to figure out how much cement you need

Most builders have to figure out how much concrete they need to make a certain structure, such as a square or round slab, a wall, square and round columns, stairs, curbs and gutters, etc. Here’s what will happen: Use geometric formulas and the building plans to figure out how much concrete is needed. Find out how dense the concrete needs to be, or estimate it based on the mix you choose.

Using the same units, multiply the volume by the density (optional) Figure out how much ready-mixed concrete you will need. For a custom mix, the last step is to figure out how much gravel, cement, and other materials you need based on the proportions you chose (percentages). Scroll down to learn more about the density of concrete and the difference between ready-mix and custom-mix concrete.

Since a certain amount of concrete is usually lost or wasted when it is being mixed and poured, it is a good idea to buy 5-6% more concrete than what is estimated, just to be safe. For example, if our concrete calculator says you need 8 tons (16,000 lbs) of concrete, you need to add at least 5% and buy a total of 8.4 tons (16,800 lbs). Use our percentage increase calculator to figure out how much an increase will be.

### Density of concrete and common bag sizes

Estimating volume is easy, but figuring out how much concrete we need is harder because we need to know the material’s density, which is usually given in kilograms per cubic meter (kg/m3). “Density in place” is another way to say it. Conventional concrete has a density between 1900 kg/m3 and 2400 kg/m3 and a compressive strength between 2500 psi and 7000 psi (pounds per square inch) 200-492 kg/cm2. It can last for 28 days after it is poured. The Portland Cement Association says that high-strength concrete has a strength between 7 000 and 14 000 psi.

The default density of standard U.S. concrete is about 2130 kg/m3, which is also the default density of this concrete calculator. However, you can change the density to get a different result. Most lightweight concrete weighs less than 1500 kg/m3, while concrete that conducts electricity weighs between 1450 and 1800 kg/m3.

Most of the time, concrete manufacturers don’t tell you the density of their mix directly. Instead, they give you the bag yield of the material. For example, a typical 80-pound bag of redymix concrete may be listed as making about 0.60 cubic feet, while a 25-kilogram bag may make about 0.01 cubic meter. With a few simple math changes, we can use this number to find the in-place density of the material and finish figuring out how much concrete we would need and how many bags we would need. You can also use our density calculator to finish the math if you already know the density and volume.

In the U.S., 80-pound and 60-pound bags are common, and some companies also make 40-pound bags. In Europe, 25 kg bags and 50 kg bags are the norm. All of these are calculated automatically by our online tool based on the metrics you choose. If you want, you can also choose a custom bag size.