Rebar Calculator

Enter rebar length, width, rebar grid dimensions, wire price and length of single rebar in the tool and it will calculate the total rebar with its cost.





Rebar-rebar (grid):




Length of a single rebar:


Rebar Calculator Image

Wire Price:



The rebar calculator calculates the total cost of rebar, grid dimension, per unit price, total rebar length, and number of rebar pieces. It also helps to find grid dimensions (length and width) to make concrete rebar calculations more precise.

What is Rebar?

A rebar is a reinforcement bar of metal used to increase the binding strength of the concrete slab. It expands along with the thermal expansion of the steel bars. The rebar spacing is different relative to the specific requirements of the construction. The rebar structural degradation of concrete structures due to reinforcement corrosion is a major worldwide problem. (Kapilesh Bhargava, June 2006)

How Do I Calculate How Much Rebar I Need? :

Rebar grid dimensions are given below:

Grid Length = Slab Length - (2 * Edge Rebar Spacing)

The rebar pieces formula.

Rebar Pieces = Total Rebars Length / Single Rebar Length

The total length of the Rebar is measured vertically and horizontally. 

Total Rebars Length = (Rebar Columns * Rebar Length) + (Rebar Rows * Rebar Width)

The Rebar cost formula is:

Cost of Rebar = Total cost (Unit cost/Unit length)

For ease, you can use a rebar estimator that estimates unit cost, and other important factors for your construction projects.

Rebar Function in Construction:

The Rebar or the reinforced bar is a steel that provides strength to the construction concrete. The rebar is utilized in various construction sites for purposes like:

  • Rebar in Grid
  • Rebar in a Wall  
  • Rebar in a Circular Slab 
  • Rebar in an Irregular Slab
  • Rebar in a Circular Slab

Rebar Example:

Let's suppose the total length of the rebar is 940 feet, the unit length is 30 feet and the unit price of the Rebar is $6.63.

Cost of Rebar = Total Cost (Unit Cost/Unit Length)
Cost of Rebar = 940 (6.36/30)
Cost of Rebar = $199.28


How Do I Know What Size Rebar To Use?

For the construction of walls, piers, or columns.  Recommended an 8mm or better quality of Rebar should be used. In the same way, for the construction of footing, foundations, etc, a better choice is 10 mm rebar. A 10 mm diameter or quality rebar is best for footers and foundations to adjust the setting

What Is The 1 8 Rule For Rebar?

Engineers sometimes use the “1/8 Rule,” which means the rebar is 1/8 thicker than a slab. For example, a slab that is 6” thicker may have rebar marked as size 6 or 3/4 inches.

Is It Better to Use Rebar or Wire Mesh?

Both wire mesh and Wire Mesh are used in the construction process. The wire mesh is restricted to slabs carrying lighter loads. Rebar on the other hand has more load-bearing required in construction. 


Wire mesh for (Sidewalks)
Rebar for (Beams, Columns, and Slabs) 

Rebar Spacing Chart:

Measurement units of rebar are the Imperial and metric bar size. Nominal diameter of Rebar in imperial and metric units is given below:

Imperial bar size Nominal diameter (in) Metric bar size (soft) Nominal diameter (mm)
#2 0.250 = 1⁄4 No.6 6.35
#3 0.375 = ​3⁄8 No.10 9.525
#4 0.500 = ​1⁄2 No.13 12.7
#5 0.625 = ​5⁄8 No.16 15.875
#6 0.750 = ​3⁄4 No.19 19.05
#7 0.875 = ​7⁄8 No.22 22.225
#8 1.000 = ​8⁄8 No.25 25.4
#9 1.128 ≈ ​9⁄8 No.29 28.65
#10 1.270 ≈ ​10⁄8 No.32 32.26
#11 1.410 ≈ ​11⁄8 No.36 35.81
#14 1.693 ≈ ​14⁄8 No.43 43
#18 2.257 ≈ ​18⁄8 No.57 57.3