How to use the rebar weight calculator
This calculator helps you convert bar diameter and total length into an estimated steel weight. It is intended for quantity takeoffs, early budgets and checks against a measured schedule. Start with the dimensions or quantities for one clearly defined item of work. Enter values in the units shown beside each field; millimetres and metres are not interchangeable.
The d²/162 relationship is a practical approximation for steel bar mass. Enter diameter in millimetres and the combined length of every bar in metres.
Worked example
A 12 mm bar weighs approximately 0.889 kg/m. A combined 100 m length weighs about 88.9 kg.
Before you order
Compare the result with your drawings and supplier information. Keep the original net quantity separate from allowances, and round purchasing quantities only at the ordering stage. Check whether delivery, labour and related materials belong elsewhere in your estimate. If the drawing or specification changes, update the inputs and record the revised basis instead of reusing an earlier total.
For the concepts behind this calculation, read Rebar (Reinforcement Steel), Rebar Grades, Unit Rate.