Rebar size chart — the bar number is its diameter in eighths of an inch (ASTM A615)
The rebar number is the diameter in eighths of an inch: #4 = 4⁄8″ = ½″ (0.668 lb/ft), #8 = 1″ (2.670 lb/ft). Weight per foot is identical across Grade 40/60/80 — grade is yield strength, not size.
What this diagram shows
A chart of US reinforcing-bar sizes showing that the bar number equals the diameter in eighths of an inch. A #3 bar is 3/8 inch and 0.376 pounds per foot; #4 is 1/2 inch and 0.668; #5 is 5/8 inch and 1.043; #6 is 3/4 inch and 1.502; #7 is 7/8 inch and 2.044; and #8 is 1 inch and 2.670 pounds per foot. Each bar is drawn at its true relative thickness, so the steady one-eighth-inch increase per number is visible. The weight per foot is the same for Grade 40, 60, and 80 steel of a given size, because grade is the yield strength, not the bar diameter.
Rebar Calculator
Free rebar calculator: exact bar count, linear feet, weight, and stock sticks to buy for slabs, driveways, footings and round pads. ASTM A615 & ACI 318.
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