Calculate rebar weight, total steel quantity, waste and estimated material cost for reinforcement bars.
Rebar Weight Calculator
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Steel Weight
Your calculated steel quantity will appear here.
Enter your bar length and number of bars to calculate.
A commonly used formula for estimating the weight of reinforcing steel is:
Bar diameter in millimeters.
Bar length in meters.
Approximate theoretical weight per meter for common reinforcement bar diameters.
| Bar Diameter | Weight / Meter | Weight / 12 m Bar |
|---|---|---|
| 8 mm | 0.395 kg | 4.74 kg |
| 10 mm | 0.617 kg | 7.40 kg |
| 12 mm | 0.889 kg | 10.67 kg |
| 16 mm | 1.580 kg | 18.96 kg |
| 20 mm | 2.469 kg | 29.63 kg |
| 25 mm | 3.858 kg | 46.30 kg |
| 32 mm | 6.321 kg | 75.85 kg |
To calculate reinforcement steel weight, first convert the bar length to meters. Select the bar diameter, enter the number of bars, and apply the formula D² × L ÷ 162.
For a 12mm bar with a length of 10 meters:
12² × 10 ÷ 162 = approximately 8.89 kg
If there are 20 bars, the theoretical weight is approximately 177.78 kg before any additional waste allowance.
Rebar quantity estimation
Beam reinforcement estimates
Column reinforcement estimates
Slab reinforcement estimates
Steel procurement planning
Construction material estimates
A common estimating formula for reinforcing steel is Weight (kg) = D² × L ÷ 162, where D is the bar diameter in millimeters and L is the bar length in meters.
A 12mm reinforcing bar weighs approximately 0.889 kg per meter using the standard D² ÷ 162 estimating formula.
A 16mm reinforcing bar weighs approximately 1.58 kg per meter.
Yes. Enter the bar length in feet and the calculator converts it to meters before calculating the steel weight.
You can add a waste allowance for cutting, laps and handling. The appropriate allowance depends on the project, bar bending schedule and procurement method.
No. This calculator is for estimating material quantity and weight. Reinforcement diameter, spacing, laps, bends and structural requirements should be determined from approved structural drawings.
This calculator provides material-weight estimates and should not be used as a substitute for structural engineering. Final reinforcement quantities should be based on structural drawings, bar bending schedules, specifications and actual site requirements.