How rebar weight is calculated
US bar sizes use published unit weights in pounds per foot. Metric bars use the common theoretical mass relationship based on diameter squared.
total weight = bar count × length × unit weight
metric kg/m ≈ diameter² ÷ 162
metric kg/m ≈ diameter² ÷ 162
Worked example
Twenty #5 bars at 20 ft each contain 400 linear feet. At about 1.043 lb/ft, the estimated weight is 417.2 lb.
Planning only: bar size, spacing, laps, hooks, cover and reinforcement design must come from the project drawings and applicable local requirements. This tool estimates material weight; it does not design reinforcement.