TMT Bar Weight Chart: 6–32 mm, and How to Check a Delivery

Quick answer: A TMT bar weighs diameter squared divided by 162, in kg per metre. A 12 mm bar is 0.889 kg per metre, so a 12 m bar is about 10.7 kg. Use the chart to estimate what a delivery should weigh, then check it against the weighing records.

Every contractor in Indore has had the argument. The invoice says 2 tonnes. The truck feels light. Nobody wants to say it out loud.

This chart estimates theoretical weight per metre. Checking a sample can help identify a size or weight discrepancy; it does not establish the total weight of a truck delivery. Check the delivery quantity against the weighing records and compare any sample result with the applicable product standard and manufacturer's documentation.

The formula

A TMT bar is a solid steel cylinder. Steel weighs about 7,850 kg per cubic metre. That gives one rule that works for every diameter:

Weight per metre (kg) = d² ÷ 162, where d is the diameter in millimetres.

So a 12 mm bar weighs 12 × 12 ÷ 162 = 0.889 kg per metre. A standard 12 metre length weighs about 10.7 kg.

Some charts print 0.888 kg per metre because they cut the decimals instead of rounding; the exact figure is 0.8889. Bars are often called "40 feet" in the market. That is 12.19 m, so a 12 mm bar of that length weighs about 10.8 kg.

TMT bar weight chart

Table scrolls sideways

IS 1786 allows a small tolerance on mass, so a real bar can sit a little under or over these numbers. A bar that is clearly lighter on every piece is not within tolerance.

How to check a delivery

1. Total weight: compare the invoiced quantity with the weighing records for the vehicle (the loaded and empty weight slips). A chart cannot settle the total of a truck.
2. Size and count: check the diameter and the number of bars in each bundle against the invoice and the bundle tags.
3. Sample, if needed: a sample can show that a size or weight is off. The sampling method, the scale and the permitted tolerance should be agreed with your engineer or the supplier and checked against IS 1786 and the manufacturer's documentation.

If something does not match, stop unloading and call the supplier. Photograph the bundle tags and the weight slips first.

Read the bar, not just the paper

Look at the bar itself:

• Rolled-in markings. A genuine TMT bar carries the maker's mark and the grade rolled into the surface at regular intervals. A bar with no markings has no traceable maker.
• Ribs. Ribs should be even, sharp and evenly spaced. Worn or uneven ribs mean a worn roll or a re-rolled bar.
• Bundle tags. A tag with a heat number, grade and size is your paper trail.
• Rust. Light surface rust is normal after a monsoon week. Flaking, pitted rust is not.

Fe 500, Fe 500D, Fe 550: which one

• Fe 500 is the common choice for houses and small buildings.
• Fe 500D has higher ductility. Engineers specify it where the structure must flex before it fails, which includes earthquake zones.
• Fe 550 and Fe 550D carry more load per bar, which can mean fewer or thinner bars on large spans.

The grade goes on the structural drawing. Do not swap it at the shop because it is cheaper that day. If your drawing says Fe 500D, the invoice should say Fe 500D.

How much steel do I need

For a rough RCC house estimate, builders in Indore often work from about 3.5 to 4.5 kg of steel per square foot of built-up area. That is only a starting point for a quote. Your structural engineer's bar bending schedule is the real number.

When you place the order, give us the diameters and the lengths from the schedule. We can then tell you how many bars and what tonnage that is. See TMT bars for what we stock and ask for a rate.

Buy binding wire with it

Every tonne of rebar needs wire to tie it. A common site rule is about 8 to 10 kg of binding wire per tonne of steel. Order it with the bars so the delivery comes together.

FAQs

What is the weight of a 12 mm TMT bar per metre?
About 0.889 kg per metre, or roughly 10.7 kg for a 12 metre bar.

How many 10 mm bars make one tonne?
About 135 bars of 12 metres each.

What does the D in Fe 500D mean?
The D stands for ductile. These bars stretch more before breaking and have better bending properties, which matters in seismic zones.

Can I buy TMT bars by the piece in Indore?
Yes. Bars are sold by weight, and a few pieces are fine for a small job. Tell us the diameter and the length.

How do I know a TMT bar is genuine?
Look for the maker's name, grade and size rolled into the bar, ask for the bundle tag, and compare the size and weight with the chart and the manufacturer's documentation.

The table and the formula were recalculated and compared with our product list on 12 October 2026. This is a catalogue check, not an independent technical review.