10M, 15M, 20M and 25M Rebar Price: How Bar Size Affects Cost

Rebar is priced by weight, so the price of 10M, 15M, 20M and 25M bar follows how many kilograms each bar carries. A 15M bar weighs twice as much per metre as a 10M, a 20M three times as much, and a 25M five times as much. Size changes the price per bar a lot, while the price per tonne changes much less, and the main exception is fabrication, where small bars cost more per tonne to cut and bend.

Below is the weight of each size by bar length, how to turn a per-tonne quote into a per-bar cost (and back), and the size-related details that change the number you're quoted.

Weight per bar for 10M to 25M

These are the four sizes that cover most residential and light commercial work. Weights are from the nominal kg per metre in CSA G30.18 (see our full rebar size chart).

A neat pattern falls out of the table: a 12 m bar of 10M weighs the same as a 6 m bar of 15M, and an 18 m bar of 10M weighs the same as a 6 m bar of 20M. Weight scales with the bar's area, and the areas of 10M, 15M, 20M and 25M are 100, 200, 300 and 500 mm².

How many bars or metres in a tonne

Flip the numbers around and you can see how far a tonne goes in each size. This is handy when a quote is per tonne and you think in bars.

To convert a per-tonne rate to a per-bar cost: multiply the bar's weight in kg by the rate, then divide by 1,000. To go the other way: divide the per-bar price by the bar weight in kg and multiply by 1,000. Doing this with a retail per-bar price usually shows a much higher rate per tonne than a contractor order, because retail pricing covers handling single bars, store overheads and small quantities.

10M rebar price: what to know

10M is the lightest Canadian size and the cheapest per bar. It shows up in slabs on ground, light walls, ties and stirrups.

• Per tonne, it is the most work to handle. A tonne of 10M is over 1,200 m of bar. If it is being cut into short pieces or bent into ties, there are many more pieces per tonne than with larger sizes, so the fabrication share of the price rises.
• It is easy to over-buy at retail. Small jobs often buy stock lengths and cut on site, which leaves offcuts. A cut list sized to your job reduces waste.
• It is not interchangeable with US sizes. 10M (11.3 mm) sits between US #3 and #4. Don't substitute either without approval.

15M rebar price: what to know

15M is the workhorse size for footings, foundation walls, grade beams and dowels, which is why "15M rebar price" is the most searched of these terms.

• Per metre, the material is about double 10M, since it weighs exactly twice as much.
• Bent 15M is common. Corner bars, L-dowels and footing hooks are bent pieces. A bent bar is priced on its full developed length, including the hooks, plus the bending work.
• Lap lengths go up with size. Larger bars need longer laps where they are spliced, which adds steel. Lap lengths come from the design; our lap splice length chart explains how they are set.

20M and 25M rebar price: what to know

20M and 25M carry more of the load in heavier footings, columns, beams and suspended slabs.

• Per bar, the price climbs fast. A 12 m bar of 25M weighs about 47 kg, five times a 12 m bar of 10M.
• Per tonne, fabrication is efficient. There are far fewer pieces per tonne, so cutting and handling are spread over more steel.
• Handling and lengths matter. Long, heavy bars need proper unloading and may need a truck with a boom or a machine on site. Very long bars can also affect what truck delivers them.
• Grade can come into it. Most work uses 400W. Where a design calls for 500W, check availability in the sizes and lengths you need, since it may not be stocked as widely.

Other size-related things that change the price

Bar size is only part of the story. Within any size, these move the number:

• Stock length vs cut to length. Bars cut to your lengths cost more in the shop but save labour and waste on site.
• Bent vs straight. Each bend is work, and complex shapes take longer than simple hooks. See what drives rebar fabrication cost for how shops price this.
• Coating. Epoxy-coated or galvanized bar costs more than plain black bar in every size.
• Quantity. A few bars of a size carry more handling cost per kilogram than a full bundle.
• Delivery. Small orders often see delivery as a larger share of the total.
• The market. Rebar prices move with steel markets, trade measures and the dollar. Our guide to rebar prices in Canada covers those factors.

Check you got the size you paid for

Because the price per bar changes so much between sizes, it is worth confirming what was delivered. 10M and 15M in particular can be confused at a glance on a busy site.

• Read the markings. Canadian bar carries rolled-in marks for the mill, size and grade along its length.
• Measure across the bar body, not the ribs. 10M is about 11.3 mm, 15M about 16.0 mm, 20M about 19.5 mm and 25M about 25.2 mm.
• Check tags against the bar list. Fabricated bundles should be tagged with the mark, size, quantity and length, and the count should match the delivery slip.

If something doesn't match, raise it before the bar is placed. Once it is tied into a mat or cast into concrete, the problem gets much harder to fix.

Choosing the size is not a pricing decision

It is tempting to look at the per-bar numbers and think about going down a size to save money. The bar size and spacing on a job are set by the design, so a change in size needs the designer's or engineer's approval. Going up a size is not automatically safer either; larger bars need more cover, longer laps and bigger bend diameters. For slabs specifically, our guide to 10M vs 15M for a slab explains how the choice is made.

Getting a price for 10M, 15M, 20M or 25M

We don't publish rebar prices online because they depend on the size mix, how much is cut and bent, the quantity and the current market. The fastest way to an accurate number is a bar list or a set of drawings.

Send us your drawings or bar list and we'll price it by size, with a free take-off if you only have structural drawings. You can also browse the rebar products we supply, from straight bar in 10M to 55M to fabricated dowels, stirrups and GFRP.