Rebar Weight Calculator
Theoretical steel bar weight from diameter and length.
How it works
Theoretical steel weight uses a circular cross-section and density of 7,850 kg/m³. Enter nominal bar diameter. Manufacturing tolerances, laps, bends and reinforcement design are separate from this estimate.
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How the Rebar Weight Calculator works
Calculate theoretical steel rebar weight from nominal diameter, bar length and bar count. The inverse mode converts a known weight into total length for the same diameter.
Weight from a circular section
The calculation uses π × diameter² / 4 and a declared steel density of 7,850 kg/m³. A 0.5 in bar is approximately 0.668 lb/ft. Ten 20 ft bars total 200 linear feet and about 133.64 lb; displayed rounding does not change the internal result.
US rebar numbers describe nominal size: enter the nominal diameter for the specified bar rather than measuring over its ribs. The default 0.5 in diameter is a quantity example.
From pounds to linear feet
Choose known weight and divide it by weight per foot. For a bundle containing multiple sizes, calculate each diameter separately; one diameter cannot describe mixed bars.
Laps, bends and cutting losses belong in the takeoff length before calculating weight. The result does not select reinforcement for a load or replace supplier scale weight. Estimate the specified concrete quantity in the footing calculator.
FAQ
Does this calculate rebar spacing? expand_more
No. It converts the diameter and quantity in your reinforcement schedule into theoretical weight.
Can I enter kilograms instead? expand_more
Yes. Change the unit system; the same formula is used after converting the input dimensions.
Is this suitable for fiberglass rebar? expand_more
No. The density assumption is for steel, so a composite product needs its own manufacturer data.