Rebar Weight Calculator

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Weight per metre and per foot from the bar diameter (d²/162), and the total in kg and tonnes for a number of bars and their length

This tool runs entirely in your browser — no file or data is sent to any server.

Enter the values

Bar diameter (d)

Number of bars

Length of each bar

Steel density (for comparison)

kg/m³

Result

Weight per metre

0.8889kg/m

Total weight

106.67kg

Total weight: 0.1067 t
Weight per foot: 0.2709 kg/ft
Total length: 120 m
Total length: 393.7 ft
Weight per metre from density (π/4 × d² × ρ): 0.8878 kg/m

A real bar's mass may differ a little from the nominal mass, within the tolerance its standard allows; weigh the bars when buying.

Working

w = d² ÷ 162 = 12² ÷ 162 = 144 ÷ 162 = 0.8889 kg/m
Total length = 10 × 12 m = 120 m
Total = 0.8889 × 120 = 106.67 kg = 0.1067 t
Check: π/4 × (12 ÷ 1000)² × 7850 = 0.8878 kg/m

Formulas

w (kg/m) = d² ÷ 162 (d in mm)
w = π/4 × d² × ρ = d² ÷ 162.2 for ρ = 7850 kg/m³
Total (kg) = w × number of bars × length (m)

d: bar diameter (mm)
ρ: steel density (kg/m³)

Assumptions

d²/162 is the usual rounding of d²/162.2, which comes from a steel density of 7850 kg/m³; the direct figure from the density is shown alongside.
The bar is taken as a plain circle of its nominal diameter; ribs need no separate allowance.

Sources: ISO 6935-2 (steel for reinforcement of concrete — ribbed bars; nominal mass from 7850 kg/m³) · B. N. Dutta, Estimating and Costing in Civil Engineering; S. C. Rangwala, Estimating and Costing

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