Calculate rebar quantities and weights from a bar schedule

Bar schedule

Mark Ø (mm) Length (m) Qty Weight (kg)
Weights use the standard steel reinforcement formula (diameter² ÷ 162 kg/m) - a nominal mass calculation, not a substitute for a structural engineer's bar bending schedule. Always confirm laps, bends and cover with the project's actual RC design.
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Total bars
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Total length (m)
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Total weight (kg)

Rebar bundle, by diameter

Weight share by diameter

DiameterBarsLength (m)Weight (kg)Share
Grouped straight from the bar schedule - useful for ordering steel by diameter or sanity-checking which bar size dominates the total tonnage.

Standard bar diameters, at a glance

DiameterNominal massTypical use
Nominal mass per metre from the standard formula (d² ÷ 162 kg/m). Typical-use notes are a general guide only - always follow the project's structural drawings and bar bending schedule for actual bar sizes, spacing and laps.

Rebar weight calculator

Work out the weight of steel reinforcement from a bar schedule. Enter each bar mark's diameter (6mm to 40mm), length in metres and quantity, and the calculator gives the weight of each line plus the total bars, total length and total weight in kg, with a breakdown by bar size for ordering steel.

It uses the standard d² ÷ 162 kg/m formula. It's free, runs in your browser with no sign-up, and there's a free Windows app too.

Worked example: steel weight for a ground beam

A ground beam has 8 H32 main bars at 9.0 m and 60 H10 links with a 2.4 m cut length. Weight per metre is d² ÷ 162, with d in mm:

  1. H32: 32² ÷ 162 = 1,024 ÷ 162 = 6.321 kg/m. 8 × 9.0 m = 72 m, so 72 × 6.321 = 455.1 kg.
  2. H10: 10² ÷ 162 = 0.617 kg/m. 60 × 2.4 m = 144 m, so 144 × 0.617 = 88.9 kg.
  3. Total: 68 bars, 216 m, 544.0 kg (about 0.54 tonnes).

The Breakdown tab shows the H32 bars make up 84% of the weight. These are nominal weights for the lengths entered - the calculator doesn't add laps or wastage, so include those in the cut lengths if your schedule doesn't already.

Questions

What is the weight of 32mm rebar per metre?

A 32mm bar weighs 6.321 kg per metre using the standard formula (32² ÷ 162). A full 12 m H32 bar therefore weighs about 75.9 kg.

What is the formula for rebar weight in kg per metre?

Weight in kg/m = d² ÷ 162, where d is the bar diameter in mm, which is the same as roughly 0.00617 × d². It comes from the cross-sectional area of the bar multiplied by the density of steel, about 7,850 kg/m³.

How do you calculate rebar weight in kg?

Multiply the weight per metre by the bar length and the number of bars. For example, 20 H16 bars at 6 m is 120 m × 1.580 kg/m = 189.6 kg. The calculator does this for every line of your bar schedule and adds up the total.

What is the weight of steel reinforcement for common UK bar sizes?

Using d² ÷ 162, nominal weights are H8 0.395, H10 0.617, H12 0.889, H16 1.580, H20 2.469, H25 3.858, H32 6.321 and H40 9.877 kg/m. Published tables can differ slightly in the third decimal place.

Does the rebar weight include laps and wastage?

No - the calculator weighs exactly the lengths and quantities you enter, so add laps into the cut lengths and allow your own wastage on top if needed. The result is an estimate for pricing and ordering, and the engineer's bar bending schedule governs the actual steel.

Rebar Weight Calculator for Windows · More free construction calculators