Rebar Weight and Size Calculator

Look up a rebar size's diameter and area, and calculate total weight for a number of bars.

⏱ Updated: 18 Sep 2026

Calculator

Free rebar weight and size calculator: look up a rebar size's diameter and area, and calculate total weight for a number of bars.

Diameter (in)
Cross-Section (in²)
Weight per Foot (lb)
Total Weight (lb)
Total Weight (kg)
Estimated Material Cost
$

Diameter, cross-sectional area, and weight per foot come from the standard ASTM A615 rebar size table — select a size to see its spec, then set the bar count and length to get a total weight.

Select a bar size and enter a bar count and length to calculate total rebar weight and cost.

How to Use the Rebar Weight and Size Calculator

Pick a bar size from the dropdown to see its diameter, cross-sectional area, and weight per foot. Add a bar count and length per bar, and total weight and cost follow.

Rebar sizes are numbered by their diameter in eighths of an inch — a #4 bar is 4/8 in. (0.5 in.) across, a #8 bar is 8/8 in. (1 in.). That naming convention is why the jump from #3 to #4 looks small on paper but the weight per foot nearly doubles: weight scales with cross-sectional area, which grows with the square of diameter, not with diameter itself.

total weight = number of bars × length per bar × weight per foot

The weight-per-foot column is the number that actually matters for ordering and shipping — rebar is sold and freighted by weight, not by the linear foot, so this is usually the last conversion between a bar count and a supplier's quote.