Reference
Reference tables
Tables worth copying, with the arithmetic that produced them printed next to them. Every figure here can be checked against its own formula before it goes anywhere near a bill of quantities.
Rebar weight chart
Mass per metre, per 12 m bar and per tonne, for every size in the metric range and for ASTM inch-pound bars. The formula is printed above the table, so any row can be checked in about ten seconds.
IS 1786ASTM A615Read →Checked 28 August 2026
Concrete grades compared
M25, C20/25 and 2900 psi describe the same concrete. M25 and 25 MPa cylinder strength do not. What each standard actually measures, and how the grade ladders line up against each other.
IS 456EN 206ACI 318Read →Checked 28 August 2026
Why these are computed, not copied
Most charts of this kind were copied from another chart, which was copied from a third. That is how a wrong digit travels, and it is why two of the rebar masses in general circulation disagree with the geometry in the last decimal place. The tables on these pages are computed at build time from the constants each standard specifies, and where a standard defines a value outright rather than deriving it, the standard's own number is quoted and labelled as quoted.