A500C rebar: weight per metre and bars per tonne

Rebar is ordered by the tonne but specified in metres. This chart converts one into the other — and shows straight away how many actual bars will arrive on site.

Rebar weight chart

What A500C means

A500 — the strength class: a yield strength of 500 MPa. C — weldable, meaning the bars can be joined by welding and not only tied with wire. This is the most widely used class for cast-in-place work in both private and commercial construction.

Plain A240 bar is used for stirrups and fixings; ribbed A500C is the working steel that carries the load.

Working it out for a foundation

For a strip foundation: take the total length of the strip, multiply by the number of longitudinal bars (usually 4 for a strip up to 60 cm deep), add stirrups at 30–50 cm spacing and 10% for laps. Divide the resulting metres by the “metres per tonne” figure from the chart.

Example: 60 m of strip × 4 bars of ⌀12 = 240 m + 10% = 264 m. The chart gives 1126 m per tonne → 0.235 t, which is about 23 bars of 11.7 m.

A tied lap must be at least 40 bar diameters: 48 cm for ⌀12. Laps are the usual reason an order falls short and more rebar has to be bought.

We stock these positions in Rolled metal.