Rebar Weight Chart Canada: kg per Metre for Every Bar Size

Canadian rebar weighs 0.785 kg per metre for 10M, 1.570 kg/m for 15M, 2.355 kg/m for 20M and 3.925 kg/m for 25M, rising to 19.625 kg/m for 55M. These are the nominal masses for CSA G30.18 bar, and they are the numbers fabricators use to turn a bar list into tonnage. The charts below give the same values per foot, per full bar and per square metre of a rebar mat.

Rebar weight per metre and per foot

Every Canadian bar size has a round-number cross-sectional area (100 mm² for 10M, 200 mm² for 15M and so on), and the nominal mass follows from that area and the density of steel. That is why the weights step up so neatly.

The kg/m values are the CSA G30.18 nominal masses, which the Reinforcing Steel Institute of Canada (RSIC) also publishes in its Manual of Standard Practice. Imperial values are conversions, rounded. If you need the diameters and areas alongside these weights, our rebar size chart has the full set of dimensions.

A shortcut worth remembering: kg per metre is the bar area in mm² multiplied by 0.00785. A 15M bar has 200 mm² of area, so 200 × 0.00785 = 1.570 kg/m. The rebar weight formula post walks through where that factor comes from.

Weight of a single bar at common lengths

Contractors often want to know what one bar weighs, whether for handling, for checking a delivery or for a quick estimate. In Canada the standard mill length is 12 m for 10M and 18 m for 15M and larger, according to the RSIC manual, so those are the longest straight bars you will normally see. Fabricated bars are cut from those lengths. Our post on standard rebar lengths explains how mill lengths and cut lengths work.

Two things stand out. First, a full-length 25M bar is already heavier than one person should be carrying around a site, and anything from 30M up at full length needs mechanical handling. Second, a bundle is a lot of steel: twenty full-length 20M bars is close to 850 kg. Our post on rebar bundle sizes covers bundle weights and what the tags tell you.

For imperial lengths, convert to metres first (1 ft = 0.3048 m). A 20 ft bar is 6.096 m, so 20 ft of 10M weighs about 4.8 kg and 20 ft of 15M about 9.6 kg.

Rebar mat weight per square metre

For slabs and walls, it is often more useful to know how much steel a square metre of reinforcement contains. The table below is for a single layer of bars running both ways at equal spacing, which is how most slab-on-grade and wall grids are drawn.

These figures are the bar mass divided by the spacing, doubled for two directions. They do not include lap splices, edge bars, extra bars at openings, dowels or chairs, all of which add weight. On a real slab, laps alone can add a noticeable amount, which is why a rebar estimate built from a proper bar list comes in heavier than a simple area calculation.

The table also shows how close some options are. 10M at 200 mm and 15M at 400 mm carry the same steel per square metre, but they are not interchangeable: crack control, bar spacing limits and the designer's intent all come into it. The size and spacing should always come from the drawings.

Why rebar weights are theoretical

Rebar is bought and sold on its theoretical mass, not a scale weight. The RSIC manual states that fabricators sell reinforcing steel on the basis of theoretical mass, calculated from the bar list using the nominal kg/m values above. That has a few practical consequences:

• Bent bars are weighed along their full length. A stirrup or an L-bar is measured along its developed length, including hooks and bends, then multiplied by kg/m.
• Actual bars vary slightly. CSA G30.18 sets limits on how far a bar's mass may fall below nominal, and real bars vary within them, so a bundle on a scale will not match the bar list exactly. That is normal and is not a short shipment.
• Each size is listed separately. Estimates and bar lists total the mass by bar size, because sizes are handled and priced separately.
• Coatings add a little mass. Epoxy or zinc coating is not in the nominal kg/m values, so ask your supplier whether a coated-bar quote counts it in the weight or lists it separately.

GFRP (fiberglass) bar does not follow this chart at all. It is far lighter than steel for a similar diameter, and its sizes are described differently. See our GFRP sizes and weights post for that material.

Using the chart on a real job

A few common ways contractors use these weights:

Turning a bar list into tonnage. Add up the total length of each size, multiply by kg/m and sum the sizes. For example, 50 bars of 15M at 12 m is 600 m, and 600 × 1.570 = 942 kg. Add 120 bars of 10M at 3 m (360 m × 0.785 = 282.6 kg) and the order is about 1,225 kg, or roughly 1.2 tonnes.

Checking a delivery. Count bars against the tag and check sizes. A rough weight check is useful for spotting a missing bundle, but do not expect scale weights to match the bar list to the kilogram. Report any shortage right away: the RSIC standard practice gives the receiver 72 hours from receipt of the load to report one to the fabricator.

Planning lifts and site handling. The single-bar table tells you when a bundle needs a lift rather than hands. For crane or forklift planning, use the bundle tag weight or the shipping list, which already totals the bars in each bundle.

Comparing quotes. If two suppliers quote the same drawings and the tonnages are very different, one of them has read the drawings differently: laps, hooks, extra bars or a missed element. Comparing tonnage by bar size is the quickest way to find where. Our guide on how rebar is priced explains what else goes into a quote besides weight.

Imperial and US bar weights

If you are working from US drawings, US bars use numbered sizes (#3, #4, #5 and up) with their own nominal weights per foot. They are close to some Canadian sizes but not identical, so a substitution changes the amount of steel in the member and needs the engineer's approval. Our post on Canadian vs US rebar sizes gives the conversions side by side.

Getting tonnage you can price

The charts above are enough for a quick check or a rough budget, but the number that matters is the tonnage from a detailed bar list: every bar, every lap, every hook. That is what a fabricator prices, cuts and bends.

If you have structural drawings, send them over for a free take-off and quote. We detail, cut, bend, tag and bundle 10M to 55M bar to your bar list and deliver across the GTA and Ontario. You can see what we supply on our rebar products page.