A concrete calculator to know how much material you need for building a concrete element. Practical examples of concrete calculators to build:
- Solid slab
- Footing
- Columns
Quantities of materials are given, such as cement, sand, gravel, steel, and water. Here you can know a lot of details about REBAR CALCULATOR AND SPACING FOR SLAB.
Concepts to Take Into account in Material Calculations to Build a Concrete Element
To build a traditional concrete slab (solid reinforced concrete slab) we need 5 basic materials:
| Materials | Imperial Units | Metric Units |
|---|---|---|
| Cement | 40 – 60 – 80 lbs bag | 25 kg |
| Sand | yd³ | m3 |
| Gravel | yd³ | m3 |
| Steel | Pounds | kg |
| Water | liters | liters |
Additives are usually used in the preparation of concrete. Additives have the function of increasing the final resistance, and accelerating or retarding the setting of the concrete. We will not take them into account, so as not to complicate the calculations.
Concrete Calculator for Slabs
Volume and Material Concrete Calculator for Slabs
How much is a Bag of Cement
- 20 bags of 50 kg of cement weigh 1 ton.
- 40 bags of 25 kg of cement weigh 1 ton.
- 55 bags of 40 pounds of cement weigh 1 ton.
- 37 bags of 60 pounds of cement weigh 1 ton.
| Pounds | Cubic Yards |
| 40 pound bag | 0.011 cubic yards |
| 60 pound bag | 0.017 cubic yards |
| 80 pound bag | 0.022 cubic yards |
Slab Thickness to Calculate How much Material do I need
It will be considered as standard slab thickness, 6 inches (150mm) , since this thickness or cant of concrete slab, allows greater constructive possibilities, which are detailed below…
- It allows greater spans or separations between supports than a 4 or 5 inches (10 – 12 cm) thick slab.
- It can have a greater amount of steel reinforcement (as necessary).
- It allows to support higher loads (use and dead loads).
- It achieves a better coverage of the reinforcement (rods), especially for areas with high relative humidity or constructions near the sea.
- It is cheaper than a slab of 7 or 8” (15 – 20 cm) height.
In summary, a 6” high reinforced concrete slab has many benefits, since it is light, economical, it can take on a greater number of reinforcing rods , and therefore greater resistance, being useful for different types of constructions or homes. All this without the need to spend extra material.
Volume and Material Concrete Calculator for Footing
Let’s see now, a material concrete calculator for columns, square and round.
Volume and Material Concrete Calculator for Columns
Waste to Calculate Materials for a Concrete Element
Economic technical indices for waste, widely accepted, are taken as references in the calculation of construction materials, which are detailed below.
| Material | % of Waste |
|---|---|
| Cement | 3 % |
| Sand | 8 % |
| Gravel | 7 % |
| Steel | 2 % |
| Water | 3 % |
Type of Concrete to Use
There are different dosages that can be used to build a concrete slab. These (dosages) depend on many factors, including the materials used (raw material).
In the following examples we will do the material calculations for,
- M20 (200kg/cm²) (20.0Mpa) concrete
- M25 (250kg/cm²) (25.0Mpa) concrete
…since these are differents TYPES OF CONCRETE, most used in construction in most countries.
For the calculation of the amount of steel or reinforcing rods in the slab, a technical index of the construction is taken. A quantity range in kilograms is suggested.
It should be taken into account that concrete slabs may need a greater or lesser amount of reinforcement (slightly reinforced slabs or highly reinforced slabs), due to their support conditions (with or without walls or intermediate beams) and the loads they are going to support. (A roof is not the same as a mezzanine).
For the exact calculation of quantities of rods, a structural project must be available.
Since the diameter of the rods that you could use is not known, the quantity is given in kg.
Keep in mind that the 3/8″ (10mm) corrugated steel bar weighs 0.413lb/ft (0.62kg/ml). In the case of the 1/2″ (13mm) corrugated steel rod, it weighs 0.66lb/ft (0.99kg/ml).
In the markets, the reinforcing steel rods are sold in strips of 40ft (12ml) and 30ft (9ml).
For the mooring, you can use wire no. 18, at a rate of 7kg for every 1000kg of reinforcing steel.
So, let’s see the calculate of the amount of material that a slab carries.
How much Material do I need to Build a Slab of 100 ft²
| For slab of 100 ft² (9.3m²) | For 600 ft³ of Concrete | For 1.70m³ of Concrete |
|---|---|---|
| Cement | 41 bags of 40 lbs | 30 bags of 25kg |
| Sand | 1.41 yd³ | 1.08 m3 |
| Gravel | 1.73 yd³ | 1.32 m3 |
| Steel | 260 to 320 lbs | 120 to 145 kg |
| Water | 374 liters | 374 liters |
| Wire | 1.0 kg | 1.0 kg |
For 250kg/cm² (25.0 MPa) of concrete
| For slab of 100 ft² (9.3m²) | 600 ft³ of Concrete | 1.70m³ of Concrete |
|---|---|---|
| Cement | 34 bags of 40 lbs | 24.5 bags of 25kg |
| Sand | 1.47 yd³ | 1.12 m3 |
| Gravel | 1.80 yd³ | 1.38 m3 |
| Steel | 240 to 300 lbs | 120 to 150 kg |
| Water | 340 liters | 340 liters |
| Wire | 1.0 kg | 1.0 kg |
For 200kg/cm² (20.0 MPa) of concrete
It may also be useful to see this REBAR SIZE CHART WITH STEEL BAR WEIGHT CALCULATOR
You can leave your doubts and comments, about construction and BEAUTIFUL HOME DESIGN PLANS , which will be answered.
It may be interesting to see all these BEDROOM PLANS with measurements.
Later you will be able to know HOW MUCH MATERIAL YOU NEED TO BUILD A ROOM.