Rebar Weight per Foot Chart for #3 to #9 Bars

US rebar weighs 0.376 lb per foot for #3, 0.668 lb/ft for #4, 1.043 lb/ft for #5 and 1.502 lb/ft for #6, rising to 3.400 lb/ft for #9. These are the nominal weights published in the ASTM bar standards, and the charts below turn them into the weight of a 20, 40 or 60 ft bar, feet per ton, and the metric equivalents. If your job is in Canada, the bars on site will be metric (10M, 15M and up), and those weights are in the last chart.

Rebar weight per foot chart (US bars)

US bar numbers are the nominal diameter in eighths of an inch up to #8: a #4 is 4/8 = 1/2 in, a #5 is 5/8 in. From #9 up the numbers are kept by convention and the diameters no longer land on an exact eighth. Our Canadian vs US rebar sizes post covers the size system and conversions in detail; this post is the weight lookup.

The large sizes, #14 (7.650 lb/ft) and #18 (13.600 lb/ft), are used mainly in heavy civil and large commercial work. Metric weights are converted from the lb/ft values and rounded.

A quick check you can do in your head: weight in lb/ft is about 3.4 times the bar area in square inches. A #5 has 0.31 in² of area, and 0.31 × 3.4 = 1.05 lb/ft. The factor comes from the density of steel, and our rebar weight formula post explains where it comes from in metric terms.

Weight of a 20, 40 and 60 ft bar

Most people searching "how much does #4 rebar weigh" want the weight of a bar they can pick up, not a per-foot number. Multiply lb/ft by the length:

Lengths of 20, 40 and 60 ft are used here as round examples; what a supplier stocks varies. Two practical points come out of the table:

• Light bars are easy to carry, heavy ones are not. A 20 ft #4 is a one-hand carry. A 40 ft #8 is already over 100 lb and awkward for one person because of its length.
• Bundles add up fast. Twenty 60 ft #6 bars is about 1,800 lb. For lifts, use the weight on the bundle tag rather than a guess. Our post on rebar bundle sizes explains what the tags tell you.

Feet of rebar per ton

Estimators and buyers often go the other way: how much bar is in a ton? A US short ton is 2,000 lb; a metric tonne is 1,000 kg (about 2,205 lb).

Rebar is bought and sold on these theoretical weights, worked out from the bar list, not on a scale weight. Real bars vary slightly from nominal within the mill tolerance, so a truck scale reading will never match the bar list exactly, and that is normal. Bent bars are weighed along their full developed length, including hooks.

Canadian metric bars in lb/ft

In Canada, rebar is made to CSA G30.18 in metric sizes. If you are working from a Canadian drawing and need imperial weights, or comparing a US product sheet to Canadian bar, use this chart. The kg/m values are the CSA nominal masses; lb/ft values are converted and rounded.

A few things to notice:

• 10M has no US twin. At 0.527 lb/ft it sits between #3 and #4. A drawing that calls for #4 cannot simply be built with 10M at the same spacing; the steel area drops, so the spacing or bar size has to be restated by the designer.
• 15M and #5 are almost identical in weight and area, which is why that pair causes the least trouble.
• Close in weight is not the same bar. The grades, deformation patterns and standards differ, and any substitution changes laps and development lengths. For the full Canadian chart in kg per metre, per full bar and per square metre of mat, see our rebar weight chart for Canada.

Using the weights on a job

Here is how the numbers get used in practice.

Turning a bar list into weight. Add up the total length of each bar size, multiply by lb/ft (or kg/m), and add the sizes together. For example, 60 bars of #4 at 20 ft is 1,200 ft, and 1,200 × 0.668 = 802 lb. Add 40 bars of #5 at 20 ft (800 ft × 1.043 = 834 lb) and the order is about 1,636 lb.

Checking a slab estimate. For a grid at equal spacing both ways, the weight per square foot is the bar weight divided by the spacing in feet, doubled. #4 at 12 in each way is about 1.34 lb per square foot before laps; #4 at 18 in is about 0.89 lb/ft². Laps, edge bars and dowels add to that, which is why a real bar list always comes out heavier than the simple calculation. Our rebar calculator and estimating guide walks through a full take-off in metric.

Identifying a bar you already have. If you have bars on site and are not sure of the size, weigh a measured length and divide: a 10 ft offcut weighing about 6.7 lb is a #4; one weighing about 5.3 lb is a Canadian 10M. Rolled markings on the bar are the more reliable way, and our post on how to identify rebar size shows what to look for. Measuring across the ribs with a tape will mislead you, because the deformations make the bar look bigger than its nominal size; see rebar nominal vs actual diameter.

Comparing quotes. If two suppliers price the same drawings and their tonnages differ a lot, one of them has read the drawings differently. Compare weight by bar size to find the gap.

Getting weights for a real project

Per-foot weights are for quick checks. The number a supplier prices, cuts and bends is the tonnage from a detailed bar list: every bar, every lap and every hook, in the bar sizes on the drawings.

We supply Canadian metric rebar from 10M to 55M, cut, bent, tagged and delivered across the GTA and Ontario. If your drawings are in US sizes but the job is in Ontario, have the engineer restate the bars in metric first, then send us the drawings for a free take-off and quote. See our rebar products and size chart for what we stock and fabricate.