Rebar Size Chart – How to Choose Sizes, Types, Grades and More

When working with concrete, construction workers and building engineers often use rebar or reinforcing bars and often need to consult a rebar size chart.

These steel bars are used with concrete to enhance the material’s tensile strength.

These reinforcing bars are usually made of steel, but base plates made of fiberglass are also available—all depending on the project you’re working on.

Fiberglass is a popular option because it’s non-magnetic and non-corrosive.

With many rebar sizes and weights and types available, it can be overwhelming to choose the best dimensions for your project.

The solution is being able to understand rebar sizes chart and markings used to denote sizing.

Sure, it’s not knowledge that you get to use daily, but it can be beneficial when you most need it

Best of all, this understanding will give you the confidence to work with the base plate regardless of the size of your next project.

Overview of Chart(s) and How to Read Them

Rebar Size Markings Chart

Each base plate usually has five different markings on it.

These contain information about the sizes of rebar, letters and symbols to indicate the producing mill and the type of steel, grade mark, and details of the central ribs.

One of the easiest ways to read this steel plate is to check on its stamped numbers and characters.

Usually, it includes three markings (for example, B6S.)

The letter B represents the manufacturer while the 6 is the grade of the base plate and is equivalent to 60, while the S is an indication that it’s made of steel.

Here we go with an overview of every element on rebar:

#1. The Rebar Size and Diameter

steel reinforcements sizes and diameters

Depending on the country, there are different rebar metric sizes. Below is the ASTM rebar sizes standard in the US, where the steel rebar sizes start from #3 to #18.

Here is the basic information about the first five sizes of rebar.

  • #3 Rebar

This size is usually made with carbon steel and used in patios, highways, road work, and driveway construction.

It’s also commonly incorporated in irregularly-shaped concrete swimming pools.

This size’s popularly is referred to as the “10 mm” because it has a rebar diameter of 10 mm in the metric system. Its rebar size in inches is 0.375 inches, which is equivalent to 9.525 mm.

The #3 rebar has a weight per length of 0.376 lbs/ft or 0.561 kg/m. And a cross-sectional area of 0.1 in2.

  • #4 Rebar

The #4 rebar is often used in residential and commercial projects to add strength in slabs and columns.

It has a diameter of 13 mm and weighs 0.668 lbs/ft with a cross-sectional area of 0.2 in2.

  • #5 Rebar

Commonly used in highways, bridges, and road construction, #5 rebar is made from carbon steel.

It’s a “16 mm” diameter rebar with a nominal diameter of 0.625 inches. It has a unit weight per length of 1.043 lb/ft and a cross-sectional area of 0.31 inch2.

  • #6 Rebar

This particular steel plate size is used in retaining walls, heavy foundations, footing construction, and highways

#6 has a 19-mm diameter, nominal diameter of 0.750 inches, a unit weight per length of 1.502 lb/ft, and a cross-sectional area of 0.44 in2.

#2. The Type of Rebar Steel

Aside from the grade and size of steel, the primary material of your steel plate and the coating used on it also counts.

  • Carbon Steel

This is the steel most commonly used in constructing commercial and residential projects and is referred to as the “Black Rebar.”

This kind of steel is cost effective and reliable when it comes to durability.

But the main drawback of this material is that it cannot handle projects that are highly exposed to moisture.

It’s susceptible to corrosion, so you might want another kind of steel if your project is located in a high-humidity area.

  • Welded Wire Fabric (WWF)

Welded Wire Fabric is produced by electrically welding a sequence of steel wires and arranging them at a right angle like a grid.

Welded wire fabric is commonly used for ground-level slabs where the earth is leveled and efficiently compacted.

These bars are also the top choice in road pavements, box culverts, drainage structures, and canal construction projects.

WWF strengthens the concrete slabs to help the concrete’s whole tensile strength.

  • Epoxy Coated Rebar

This is your ideal choice when working on projects that are mostly exposed to high moisture and high humidity.

And although this is one of the more expensive ones, you can rely on it to be intact despite the continuous contact with seawater and moisture.

As the name suggests, this steel plate is coated with thick epoxy that helps slow down corrosion.

  • Sheet Metal Reinforcing Bars

Sheathing made from annealed sheet steel pieces are then bent into a corrugated shape.

These bars are primarily used in roof construction, stair formations, and floor slabs.

Sheet metal base plates also have standard 1/6-inch holes punched at regular distances.

  • Stainless Steel

A favorite alternative to carbon steel bars, this is a viable choice if you want the reliability of carbon steel while enjoying the corrosion-resistance feature of stainless steel.

It’s not as low-priced as carbon steel; stainless steel costs almost eight times more.

This is the best option for projects related to roads, bridges, piers, and other structures that handle immense weight.

  • Galvanized Rebar

Suitable for structures that need an excellent foundation, these sheathings are up to forty times more resistant to corrosion than carbon steel.

True to its undeniable strength, galvanized sheathing is also pegged as the most expensive among the kinds of steel plate because it is alloy steel dipped in a zinc solution to help battle corrosion.

  • Glass Fiber Reinforced Polymer (GFRP)

GFRP is your best choice when your project has exposed structure and is in contact with water.

The promise of this material is that corrosion will never be an issue, and it has a far better tensile strength despite being 75% lighter than steel plates.

#3. Rebar Grade

rebar grade sizes example

You will need to understand the definition and difference of tensile strength and yield strength to identify what rebar grade is suitable for your project.

Consider tensile strength and the yield strength as the maximum and minimum stress capability of a steel plate grade.

Tensile strength refers to the maximum limit of stress your material can handle before it breaks.

Yield strength is the minimum stress that it can be subjected to before deformation.

ASTM sets the rebar grades, and the standard grades are 40, 60, 75, 80, and 100.

This indicates the level of yield of a particular sheathing.

For example, if the base plate has a grade of 40, then its minimum yield strength is 40 KSI, which is equivalent to 40,000 PSI.

Example of Using the Rebar Chart

For this example, “W” represents the manufacturer of the rebar.

The following marking is “10,” which is indicative of the bar size.

If you refer to the rebar size table below or download a rebar sizes chart pdf, you’ll know that the base plate size is #3 with the following dimensions:

Bar Size

Metric Rebar Sizes

(lb/ft)

(kg/m)

(inch)

(mm)

(in2)

(mm2)

#3

#10

0.376

0.561

0.375

9.525

0.11

71

The table below can give you a better way to read diameter sizes in the base plate to ensure that you have the right size for whatever you are working on.

“S” stands for carbon steel as the primary material of the bar, and the grade “60” means that the base plate has a minimum yield strength of 60 KSI, which is equivalent to 60,000 PSI.

Charts

Rebar Size Chart, Rebar weight chart, Rebar Diameter Chart – American rebar sizes

Imperial

“Soft”

Mass per unit length

Nominal Diameter

Nominal Area

Bar Size

Metric Rebar Sizes

(lb/ft)

(kg/m)

(inch)

(mm)

(inch2)

(mm2)

#2

#6

0.167

0.249

0.25

6.35

0.05

32

#3

#10

0.376

0.561

0.375

9.525

0.11

71

#4

#13

0.668

0.996

0.5

12.7

0.2

129

#5

#16

1.043

1.556

0.625

15.875

0.31

200

#6

#19

1.502

2.24

0.75

19.05

0.44

284

#7

#22

2.044

3.049

0.875

22.225

0.6

387

#8

#25

2.67

3.982

1

25.4

0.79

509

#9

#29

3.4

5.071

1.128

28.65

1

645

#10

#32

4.303

6.418

1.27

32.26

1.27

819

#11

#36

5.313

7.924

1.41

35.81

1.56

1006

#14

#43

7.65

11.41

1.693

43

2.25

1452

#18

#57

13.6

20.284

2.257

57.3

4

2581

#18J

14.6

21.775

2.337

59.4

4.29

2678

Rebar Size Chart, Rebar Weight Chart, Rebar Diameter Chart – Canada Rebar Sizes

Metric Bar Size

Mass per unit length (kg/m)

Nominal diameter (mm)

Cross-Sectional Area (mm2)

10M

0.785

11.3

100

15M

1.57

16

200

20M

2.355

19.5

300

25M

3.925

25.2

500

30M

5.495

29.9

700

35M

7.85

35.7

1000

45M

11.775

43.7

1500

55M

19.625

56.4

2500

Steel Types

Symbol

Steel Type

S

Carbon Steel

A

Axle Steel

W

Low-Alloy Steel

SS

Stainless Steel

CS

Low Carbon Chromium

Rebar Grade Chart

Grade Mark

Maximum Yield Strength

PSI

40

40 KSI

40,000 PSI

60

60 KSI

60,000 PSI

75

75 KSI

75,000 PSI

80

80 KSI

80,000 PSI

100

100 KSI

100,000 PSI

A DIY Project Using Rebar

small rebar project ex

Working with rebar is manageable, especially if you have the right tools and readily available materials.

You can even try a DIY project at home with rebar as the main module.

If you have a garden, you can try building a charming archway with rebar.

This arch can be the stairway for vines, and eventually, you’ll have it filled with crawling greens that you won’t see any signs of rebar.

Create your own not-so-secret garden with this rebar project.

The materials you need for this project are:

  • Cable ties
  • 18-gauge copper wire
  • 1 ½-inch by 10-feet rebar for the stakes
  • 2 ½-inch by 20-feet rebar for the arches
  • 2 3/8-inch by 20-feet rebar for the circles
  • Plastic garage door stop molding or another stiff but 100% bendable material

These are the tools you’ll need:

  • Chalk bottle
  • Clamp
  • Conduit bender
  • Hacksaw
  • Marker
  • Rubber mallet
  • String
  • Tape measure

Here are the steps to create this no-welding metal garden arch trellis:

#1. Create the swooping yet delicate arch using the ½-inch rebar and make a simple bending leap on the ground.

Cut the 10-feet rebar into ten 10-inches stakes and saw about 2/3 of the rebar using a hacksaw before snapping off the stake.

#2. Drive one rebar stake into the ground and tie a 3-feet string to it.

Pull the line taut to create a compass—this will be your guide to create that perfect 3-ft radius arch and mark it with chalk.

#3. Have the other nine stakes settled evenly—about 5-inches deep to the ground—to create the semicircle using the chalk outline as a guide. Mark the middle stake with a string.

#4. It’s time to bend the rebar into a semicircle shape.

Note that rebar may kink when bent, so this is where the plastic garage door-stop molding comes in handy.

Place it between the rebar and the stakes to help soften the bend.

#5. Connect the arches with circles made from the 3/8-inch by 20-feet rebar.

Cut the rebar into 4-feet lengths, and then bend it to form a circle using a conduit bender.

You need nine rebar circles for this project.

#6. You are ready to assemble your arch and create the holes for the anchors.

Lay out the footprint on your yard or any flat surface and set the anchor holes for the trellis 6-feet apart and 12-inches between arches.

Drive the stakes to create the hole markings and then pull the stakes out.

#7. To ensure that your trellis is stable, you have to embed each arch’s end about 18-inches deep into the ground.

Measure this distance and mark your rebar to know how far you have to sink it in.

#8. Start adding the rebar circles with the first one about 2 feet up from the bottom of your rebar arch.

You can temporarily secure the loops with cable ties so you can adjust accordingly if needed.

Spread the circles evenly around the arch. You can permanently arrange the circles using the copper wire when all set.

Frequently Asked Questions

What is a stirrup in rebar?

A stirrup is mainly used in concrete columns and beams to support the primary longitudinal sheathing.

These are usually rectangular and square with five 90-degree bends. Like the conventional steel plate, there are also different stirrup rebar sizes.

Can you bend and cut the rebar to get the right size?

Getting the right size upon purchase is recommended to save you energy and time.

But in instances where the situation calls for you to bend and reduce the size of the base plate, you can as long as you have the proper tools.

You can use a bolt cutter or a hacksaw if the steel plate is thin and you are not planning to cut a massive batch of sheathing.

Alternatively, you can also use an angle cutter equipped with a cutting wheel to get the job done.

When you are cutting sheathing, you only need to cut through half of it. Once that’s done, it will already be easy for you to break it in half.

What does this mean for you? Time and power saved.

Bending this base plate is simple and doable, especially if the diameter is not too thick. You can bend it by hand as long as you have enough leverage.

But if you are working with thicker ones, you can opt to purchase or borrow a rebar bender.

Check this video for starters:

What are the most commonly used rebar sizes?

The most commonly used sheathings are #4 and #5.

These are must-haves for any residential construction and are almost always used in commercial projects.

These sizes are strong enough, especially when used in multiples, to support the weight of these structures.

What is the proper spacing when laying out rebar?

Rebar is intended to form a grid pattern.

When laying rebar, make sure that you observe about 12-inches spacing in between.

What happens if you use the wrong size rebar?

The primary task of this steel plate is to prove reinforcement to your concrete structure.

If you end up placing the wrong size of base plate, you are compromising the reinforcement required for your project’s integrity and strength.

No, the building will not automatically crumble and collapse, but the longevity and durability of the structure are minimized up to 35%.

This is not something you want to look forward to anyway, so build it right from the start!

Summary

Concrete plays a non-negotiable responsibility in construction, but it loses its purpose and value without rebar.

Now that you know all about rebar and the size charts, you can confidently identify suitable steel and concrete rebar sizes for your next project to create a foundation, wall, or walkway that can last for years.