Rebar Catalogue - Bar Sizes, Areas & Weights

What this catalogue covers

This is a reference table of reinforcing bar sizes under four standards: EN 10080 with Eurocode 2, ASTM A615 and A706 for American work, TCVN 1651 with TCVN 5574 for Vietnam, and BS 4449 for the UK. It holds 43 bar sizes in total, each with its nominal diameter, cross-sectional area, mass per metre, perimeter and the grades it is produced in, and each has its own reference page.

Keeping four standards side by side matters because the same physical bar is named differently in each. A 16 mm bar is "16" under EN and TCVN, "H16" under BS 4449, and has no exact ASTM twin - the nearest American sizes are #5 at 15.9 mm and #6 at 19.1 mm. Substituting by name rather than by area is a common and expensive mistake.

EN 10080 / Eurocode 2

11 sizes - 6 to 40 mm, grades B500A, B500B, B500C

TCVN 1651 / TCVN 5574

13 sizes - 6 to 40 mm, grades CB300-V, CB400-V, CB500-V

ASTM A615 / A706

11 sizes - #3 to #18, grades 60, 75, 80

BS 4449

8 sizes - H8 to H40, grades B500A, B500B, B500C

Total

43 bar sizes, each with its own reference page

Bar area and mass by size

The two numbers asked for most often are the cross-sectional area, which sizes the reinforcement, and the mass per metre, which prices it and determines what the steel fixers can lift. For metric bars both follow directly from the nominal diameter: area is pi/4 times diameter squared, and mass is that area times the density of steel, 7,850 kg/m³.

8 mm (H8)

Area 50.3 mm², mass 0.395 kg/m

10 mm (H10)

Area 78.5 mm², mass 0.617 kg/m

12 mm (H12)

Area 113.1 mm², mass 0.888 kg/m

16 mm (H16)

Area 201.1 mm², mass 1.578 kg/m

20 mm (H20)

Area 314.2 mm², mass 2.466 kg/m

25 mm (H25)

Area 490.9 mm², mass 3.853 kg/m

32 mm (H32)

Area 804.2 mm², mass 6.313 kg/m

40 mm (H40)

Area 1,256.6 mm², mass 9.864 kg/m

These are identical under EN 10080, TCVN 1651 and BS 4449 - the standards differ in grade designation and testing, not in the geometry of a 16 mm bar. Only the grade names and the characteristic yield strength change: 500 MPa for EN and BS, and 300 to 500 MPa for TCVN depending on the CB grade specified.

ASTM bar sizes

American bar sizes are numbered in eighths of an inch for #3 to #8, so a #4 bar is nominally four eighths, or half an inch. Above #8 the numbering stops tracking the diameter and #9, #10, #11, #14 and #18 are defined by area instead, which is why the jump from #11 to #14 is much larger than the numbers suggest.

#3

9.5 mm, area 71 mm² (0.11 in²), mass 0.56 kg/m

#4

12.7 mm, area 129 mm² (0.20 in²), mass 0.994 kg/m

#8

25.4 mm, area 510 mm² (0.79 in²), mass 3.973 kg/m

#11

35.8 mm, area 1,006 mm² (1.56 in²), mass 7.907 kg/m

#14

43.0 mm, area 1,452 mm² (2.25 in²), mass 11.38 kg/m

#18

57.3 mm, area 2,581 mm² (4.00 in²), mass 20.24 kg/m

The ASTM areas are the published values from A615 Table 1, which are rounded to the nominal in² figure rather than computed from the diameter. A #4 bar is listed as 0.20 in² (129 mm²) although pi/4 times 12.7 mm squared gives 126.7 mm². Use the tabulated value: it is what the standard specifies and what a checker will expect.

Area for a group of bars, and area per metre

Reinforcement is rarely specified as a single bar. Two derived tables cover the two ways it is actually called up on a drawing. The first gives the total area for n bars of a size, for beam and column reinforcement where you specify a count. The second gives area per metre width at a bar spacing, for slabs and walls where you specify a pitch.

Area per metre is the bar area multiplied by 1,000 divided by the spacing in millimetres. A 12 mm bar at 200 mm centres gives 113.1 x 1000 / 200 = 566 mm² per metre, which is the number that goes against the As,req from your slab design. The catalogue tabulates this for every bar size at the usual spacings so you can read across to the first arrangement that satisfies the requirement.

Area for n bars

n x single-bar area - for beams and columns specified by bar count

Area per metre

area x 1000 / spacing - for slabs and walls specified at centres

Worked example

12 mm at 200 mm centres = 113.1 x 1000 / 200 = 566 mm²/m

Common questions