Rebar Weight Calculator

Calculate reinforcement steel weight by quantity or by spacing — with a per-diameter breakdown.

Bars by quantity

For beams, columns, stirrups — anywhere you know the exact bar count.

No spacing-based entries added — used for slabs/mats where bars run at a fixed spacing.

Lap / cutting wastage %

Covers splice overlaps and offcuts — typically 3–8% depending on how many joints your layout needs.

Price per kg

Leave blank to skip cost estimate.

Tap a size to add it as a new "by quantity" bar entry.

Steel density (kg/m³)

Stock bar length (m)

Weight by diameter (kg/m)

Using w = d² × density × π ÷ 4,000,000 (the common d²/162 approximation at 7850 kg/m³)

Add your bar entries, then press Calculate — results will appear here.