Rebar quantity calculator
Estimate outputs: Length with allowance, Whole stock bars, Estimated mass. Adjust Required bar length, Stock piece length, Lap and cutting allowance to match your project.
Estimate outputs: Length with allowance, Whole stock bars, Estimated mass. Adjust Required bar length, Stock piece length, Lap and cutting allowance to match your project.
Inputs and units
Use the units shown beside each field. Replace the sample values with your measurements and the figures on the selected product packaging.
| Parameter | Example input |
|---|---|
| Required bar length | 180 m |
| Stock piece length | 12 m |
| Lap and cutting allowance | 12 % |
| Bar weight per metre | 0.888 kg/m |
Formula and assumptions
Length with allowanceRequired bar length × (1 + Lap and cutting allowance / 100)
Whole stock barsceil(Length with allowance / Stock piece length)
Estimated massLength with allowance × Bar weight per metre
ceil = round up; floor = round down; max = the greater value. Trigonometric angles are converted from degrees to radians.
Allowance is applied before rounding to whole packages. Whole units are rounded up; displayed decimals are rounded only for readability.
Geometry and material quantities do not determine load capacity or reinforcement design. Use dimensions specified in the project.
Worked example
Sample values are examples, not product specifications. Run the calculation again with your own measurements.
| Result | Calculation |
|---|---|
| Length with allowance | 201.6 m |
| Whole stock bars | 17 |
| Estimated mass | 179.0208 kg |
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