Why you need a real weight chart
On most sites the foreman will shout a weight number from memory. That number is rarely the exact weight of the bar you get. A 12mm TMT that actually weighs 0.88 kg per metre can be billed as 1 kg and you end up paying for phantom steel. Knowing the exact weight per piece, per metre and per bundle lets you verify the invoice against the delivery.
IS 1786 formula and Fe 500D density
The Indian standard IS 1786 gives a simple weight formula for steel rods:
- Weight (kg per metre) = d2 x 0.00617
- d = diameter in millimetres
- 0.00617 is derived from the density of Fe 500D (~7850 kg/m3)
Plug the diameter, multiply by the length you need and you have the exact weight. No guesswork.
Weight chart for 6 mm to 25 mm
| Size (mm) | Weight per piece (1 m) (kg) | Weight per metre (kg) | Typical bundle (12 pcs x 12 m) (kg) |
|---|---|---|---|
| 6 | 0.22 | 0.22 | 32 |
| 8 | 0.39 | 0.39 | 57 |
| 10 | 0.62 | 0.62 | 89 |
| 12 | 0.89 | 0.89 | 128 |
| 16 | 1.58 | 1.58 | 227 |
| 20 | 2.47 | 2.47 | 355 |
| 25 | 3.86 | 3.86 | 555 |
Numbers are rounded to two decimals. The bundle weight assumes the common Indian bundle of 12 rods, each 12 m long (total 144 m). If your supplier uses a different bundle size, just scale the weight accordingly.
Quick weight calculator
Want to check a custom length? Use this one-liner:
Weight (kg) = (Diameter2 x 0.00617) x Length (m)
Example: 16 mm bar, 6 m length
Weight = (162 x 0.00617) x 6 = 1.5795 x 6 ~ 9.48 kg.
Multiply the result by the current market price (Rs. 55-60 per kg for Fe 500D) to get a ball-park cost. A 16 mm, 6 m bar will cost roughly Rs. 525-570.
Typical price range in 2026
Across major brands-Tata Tiscon, JSW, Kamdhenu, and Jindal-the price per kilogram of Fe 500D TMT sits between Rs. 55 and Rs. 60. Premium brands like Tata Tiscon may charge Rs. 58-60, while Kamdhenu often stays at Rs. 55-57. The difference is usually due to surface finish and traceability, not strength.
So a 12 mm bundle (~128 kg) will run Rs. 7,040-7,680 depending on the brand you pick.
Common frauds you'll meet on site
- Light-weight bars sold as full weight - Supplier mixes in 10 % thinner rods but still charges you for Fe 500D weight.
- Shorter pieces - A "12 m" rod is actually 10.8 m. Over a bundle that shaves off 172 kg, which translates to a Rs. 9,000 loss.
- Wrong diameter in the bundle - You order 12 mm, get a few 10 mm pieces mixed in. The invoice still shows 12 mm weight, so you overpay.
- Fake "Fe 500D" grade - Bars stamped Fe 500 but chemically tested as Fe 415. They pass visual check but fail the tensile test.
- Bundling fraud - Supplier tells you a bundle is 12 pcs x 12 m, but actually delivers 10 pcs x 12 m and adds two 8 mm rods to make up the weight.
The most common one is the short-length trick. Always ask for a measuring tape and verify at least two rods from every bundle.
How to verify on the spot
Carry a simple steel scale (digital or mechanical) that can handle up to 70 kg. Weigh a single 12 mm rod; it should read between 0.86 kg and 0.91 kg. If it's lighter, push back.
Ask for a cut-off certificate that shows the exact length of each rod. If the supplier hesitates, walk away. Good contractors will have the paperwork ready.
Related reads
Related: 16mm Rod Weight Per Piece and Per Meter 2026 - Complete Chart for Indian Construction
Related: 12mm Ka Sariya 1 Bundle Mein Kitna Hota Hai - 2026
Related: Rungta Steel Price Today 2026 - 8mm, 10mm, 12mm, 16mm Rate Per Kg
Bottom line: keep the formula, keep a scale, and never accept a bundle without checking the length and weight. If the numbers don't line up, you're being short-changed.
Bundle Quantity, Truck Loading and Site Storage Tips
Most Indian suppliers ship TMT rods in the standard "12 pcs × 12 m" bundle, but the actual count can vary with diameter. Below is a quick reference:
| Diameter (mm) | Rods per bundle | Total length per bundle (m) | Bundle weight (kg) |
|---|---|---|---|
| 6 | 12 | 144 | 32 |
| 8 | 12 | 144 | 57 |
| 10 | 12 | 144 | 89 |
| 12 | 12 | 144 | 128 |
| 16 | 12 | 144 | 227 |
| 20 | 12 | 144 | 355 |
| 25 | 12 | 144 | 555 |
Typical tipper trucks in Delhi-NCR, Mumbai and Bengaluru carry 9-10 MT of steel. That translates to roughly 4-5 bundles of 25 mm rods or 12-15 bundles of 12 mm rods per load. When you receive a truck, verify the number of bundles against the weight shown on the truck's weighbridge slip.
Site storage is a frequent cause of accidental loss. Follow these practices:
- Lay bundles on a flat, non-slippery surface - concrete pads are ideal.
- Stack only two rows high; the bottom row should be placed with the rod ends resting on a wooden pallet to avoid direct ground pressure.
- Do not place heavy objects on top of the bundles; a 25 mm bundle can deform under a 500 kg load.
- Leave a 30 cm clearance between stacks to allow airflow and prevent rust buildup.
- Label each stack with diameter, length and bundle count; a simple colour-coded tag system (green-6 mm, blue-12 mm, red-20 mm) saves time during site audits.
What Tata Tiscon, JSW Neosteel, SAIL and Kamdhenu actually weigh on the weighbridge
Manufacturers quote theoretical weights based on IS 1786, but real-world weighbridge readings show a small tolerance band. The table below summarises the average measured weight per metre for the most common diameters in 2026:
| Brand | Diameter (mm) | Theoretical (kg/m) | Measured (kg/m) | Tolerance (%) |
|---|---|---|---|---|
| Tata Tiscon | 12 | 0.89 | 0.92 | +3.4 |
| JSW Neosteel | 12 | 0.89 | 0.87 | -2.2 |
| SAIL | 12 | 0.89 | 0.90 | +1.1 |
| Kamdhenu | 12 | 0.89 | 0.88 | -1.1 |
| Tata Tiscon | 20 | 2.47 | 2.53 | +2.4 |
| JSW Neosteel | 20 | 2.47 | 2.45 | -0.8 |
| SAIL | 20 | 2.47 | 2.48 | +0.4 |
| Kamdhenu | 20 | 2.47 | 2.46 | -0.4 |
The ±3 % variation is within the permissible limits set by IS 1786 (±5 %). However, when you purchase large quantities, these few kilograms add up. For a 12 m bundle of 20 mm rods, the difference between Tata's 2.53 kg/m and JSW's 2.45 kg/m equals about 1.44 kg per rod, or Rs. 85-90 per bundle at Rs. 60 per kg.
Always ask the supplier for the latest weighbridge certificate; reputable brands keep a digital log that can be shown on a tablet.
How contractors cheat on TMT weight - 4 common frauds
Even with a weight chart, dishonest contractors can manipulate the numbers. The four most prevalent tricks in 2026 are:
- Short-length substitution - A "12 m" rod is actually 11.5 m. Over a 12-rod bundle this saves 6 m of steel, roughly 5 kg for a 12 mm bar and Rs. 300-350 in cost.
- Diameter downgrade - Supplying 11.5 mm rods but stamping them as 12 mm. The weight loss is about 7 % (0.82 kg/m vs 0.89 kg/m). The visual difference is hard to spot without a caliper.
- Rib profile tampering - Some manufacturers use a shallow rib on cheaper grades to reduce weight while keeping the same diameter marking. The weight difference can be 4-5 % and the bar's flexural strength drops noticeably.
- Weight-tag swap - Bars from a lower-priced brand (e.g., Kamdhenu) are re-tagged with a premium brand's label (e.g., Tata). The weighbridge reading matches the label, but the chemical composition may be Fe 415 instead of Fe 500D.
How to protect yourself:
- Inspect at least two rods from each bundle with a steel ruler and a digital caliper.
- Ask for the batch number and cross-check it on the manufacturer's portal.
- Use a portable 70 kg scale to verify the weight of a single rod before signing the delivery challan.
- Insist on a signed "cut-off certificate" that records the exact length of every rod in the truck.
TMT vs HYSD vs CTD bars: weight differences in 2026
India's construction market still sees legacy HYSD (High Yield Strength Deformed) and CTD (Cold Twisted Deformed) bars on smaller projects, but modern Fe 500D TMT has become the norm. The table compares the three types for the most common diameters:
| Diameter (mm) | HYSD (kg/m) | CTD (kg/m) | TMT Fe 500D (kg/m) | Weight difference vs TMT |
|---|---|---|---|---|
| 12 | 0.84 | 0.86 | 0.89 | +3.6 % (TMT heavier) |
| 16 | 1.49 | 1.53 | 1.58 | +3.2 % (TMT heavier) |
| 20 | 2.33 | 2.39 | 2.47 | +3.5 % (TMT heavier) |
| 25 | 3.55 | 3.65 | 3.86 | +5.4 % (TMT heavier) |
While TMT bars are slightly heavier (3-5 % more) than HYSD/CTD of the same size, they offer 30-40 % higher yield strength and better ductility, reducing the required bar count in beams and slabs. The marginal weight increase is offset by lower concrete consumption and reduced labour for tying.
For a typical 1200 sq ft residential slab, switching from 12 mm HYSD to Fe 500D TMT can save up to 1 % of the total steel weight while increasing the overall safety factor.
Calculating total steel for a 1200 sq ft house using this chart
Assume a conventional two-storey house with the following structural elements:
- Foundation: 150 m of 25 mm bar, 12 m length each.
- Ground floor columns: 20 pieces of 20 mm bar, 3 m each.
- Ground floor beams: 30 m of 16 mm bar.
- First floor slab (1200 sq ft): 2 kg of steel per sq ft (average), using 12 mm and 16 mm bars.
- Roof trusses: 80 m of 12 mm bar.
Step-by-step calculation:
- Foundation: 150 m × 3.86 kg/m (25 mm) = 579 kg.
- Columns: 20 × 3 m × 2.47 kg/m (20 mm) = 148 kg.
- Beams: 30 m × 1.58 kg/m (16 mm) = 47 kg.
- Slab: 1200 sq ft × 2 kg/sq ft = 2400 kg. Split 60 % 12 mm (0.89 kg/m) and 40 % 16 mm (1.58 kg/m). Approx. 1440 kg of 12 mm (~1618 m) and 960 kg of 16 mm (~607 m).
- Roof: 80 m × 0.89 kg/m = 71 kg.
Total steel = 579 + 148 + 47 + 2400 + 71 = 3,245 kg (~3.25 MT). Using the 2026 price of Rs. 58 per kg for Tata Tiscon, the material cost is about Rs. 188,000. If you opt for Kamdhenu at Rs. 55 per kg, the cost drops to Rs. 179,000 - a saving of Rs. 9,000, which is roughly the weight of one 25 mm bundle.
This example shows how the weight chart, combined with the IS 1786 formula, lets you budget accurately and verify that the delivered steel matches the design estimates.
