Steel bars are a common element in construction and manufacturing projects. Strong and versatile, these bars come in various types such as TMT bars, Mild Steel bars, deformed bars, steel rebars, reinforced bars, each with its unique properties and applications.

Understanding the weight of steel bars, therefore, is crucial for project planning, budgeting, and procurement. Referring to a steel bar weight chart, therefore, can be an invaluable reference tool.

Further, for industry professionals, knowledge of steel bar weight in kg enables resource allocation and cost estimation. Here, let us take a look at how to calculate the unit weight of steel bars and what a steel bar weight chart looks like.

Disclaimer: The focus here is to understand the process of steel bar weight calculations and how to prepare a weight chart for reference. The dimensions used below are for reference only. All should consult with their steel manufacturer for exact dimensions and sizes for the weight calculation.

Steel bar weight chart

The quickest way to plan steel procurement is to start with unit weight, then convert it into 12 m bar weight and tonne requirements. Unit weight is simply kg per metre (kg/m). Once kg/m is known, estimation becomes straightforward, and delivery checks become easier.

So, before we learn how to calculate the unit weight of steel bars, let’s take a look at the steel bars weight chart in kgs for TMT bars, MS bars, deformed bars, and more.

TMT bar weight chart

(Updated: Jan 2026 | All weights in kg, length = 12m)

Diameter (mm)	Weight of a single bar (12m)	Number of bars in a bundle	Unit weight per metre (kg/m)	Number of bars in a ton	Approx Price (₹/kg)
8	4.74	10	0.395	211	₹56.1
10	7.41	10	0.617	135	₹56.1
12	10.67	10	0.889	93	₹56.1
16	18.96	5	1.580	52	₹56.1
20	29.63	5	2.469	34	₹56.1
25	46.30	2	3.858	22	₹56.1
32	75.85	2	6.321	13	₹56.1
36	96.00	1	8.000	10	₹56.1

*For reference only. Please check with your steel seller for precise size, price, weight, and other details.

MS Round bars weight chart

Weight chart with approximate price (Jan 2026)

Size (mm)	Weight (kg/ft)	Weight (kg/m)	Approx. Price (₹/kg)
8	0.120	0.395	₹47.81
10	0.188	0.617	₹47.31
12	0.271	0.889	₹47.31
14	0.369	1.210	₹47.11*
16	0.482	1.580	₹47.11
20	0.753	2.469	₹47.11

*For reference only. Please check with your steel seller for precise size, price, weight, and other details.

Deformed reinforcing steel bar weight chart

Weight chart with approximate price (Jan 2026)

Size (mm)	Weight (kg/ft)	Weight (kg/m)	Approx. Price (₹/kg)
8	0.120	0.395	₹56.0
10	0.188	0.617	₹56.0
12	0.271	0.888	₹56.0
14	0.369	1.210	₹56.0
16	0.481	1.580	₹56.0
20	0.753	2.469	₹56.0
25	1.176	3.858	₹56.0
28	1.473	4.832	₹56.0
32	1.930	6.321	₹56.0
36	2.444	8.000	₹56.0
40	3.001	9.870	₹56.0

*For reference only. Please check with your steel seller for precise size, price, weight, and other details.

Hot-rolled steel bar weight chart

Weight chart with approximate price (Jan 2026)

Hot-rolled MS round bars are widely used in fabrication, machining, repair works, and industrial maintenance. The weight is standardised by diameter, so a clean chart helps MSMEs avoid billing surprises and check whether the received material matches the PO.

Common fabrication sizes

Diameter (mm)	Unit weight (kg/m)	Approx pieces in 1 tonne (6m)	Indicative price (₹/kg)	Approx price (₹/m)
8	0.40	421.94	47.81	19
10	0.62	270.12	47.31	29
12	0.89	187.69	47.31	42
16	1.58	105.49	47.11	74
20	2.47	67.48	47.11	116
25	3.85	43.29	47.11	181
28	4.83	34.51	46.61	225

*For reference only. Please check with your steel seller for precise size, price, weight, and other details.

Heavy round bars used for shafts and industrial components

Diameter (mm)	Unit weight (kg/m)	Approx pieces in 1 tonne (6m)	Indicative price (₹/kg)	Approx price (₹/m)
30	5.55	30.03	46.61	259
32	6.31	26.41	46.61	294
34	7.14	23.34	46.61	333
36	7.99	20.87	46.61	372
40	9.85	16.92	46.61	459
45	12.50	13.33	46.61	583
50	15.40	10.82	46.61	718
60	22.20	7.51	47.41	1,053

*For reference only. Please check with your steel seller for precise size, price, weight, and other details.

Often missed in MSME buying: Invoice weight vs received weight

A common issue is mismatch between what was estimated and what was billed. This happens when estimation is done using kg/m, but billing is done on actual weighbridge weight. A simple reconciliation discipline reduces disputes and prevents silent leakage.

PO vs Delivery vs Invoice Reconciliation (Reference Table)

Assumption: For expected-weight calculation, we are using here 12m bar length.

Diameter (mm)	Ordered qty (pcs/MT)	Expected weight (kg)	Received pieces	Weighbridge weight (kg)	Variance (kg)	Remark
8	200 pcs	948.0	200	952.0	+4.0	Within normal tolerance, close the GRN
10	100 pcs	741.0	98	726.0	-15.0	Short by 2 pcs, raise shortage note and verify bundle tags
12	120 pcs	1280.4	120	1272.0	-8.4	Slight negative, check supplied length and rolling tolerance
16	60 pcs	1137.6	60	1145.0	+7.4	Acceptable variance, ensure MTC is attached
20	30 pcs	888.9	30	884.0	-4.9	Acceptable variance, record and move on
25	20 pcs	926.0	20	918.0	-8.0	Verify weighbridge slip number on invoice, then close
32	10 pcs	758.5	9	684.0	-74.5	1 bar missing, hold payment till corrected or credited
36	5 pcs	480.0	5	482.0	+2.0	Within normal tolerance, close the GRN

How to calculate the key fields (simple rule):

• Expected weight (kg) = Ordered pieces × 12m bar weight (kg) for that diameter, or = Ordered MT × 1000 (if ordered in MT).
• Variance (kg) = Weighbridge weight − Expected weight.

Practical tip for MSMEs: Bundle packing differs by supplier. Count pieces by diameter at unloading, record the weighbridge slip number, and attach the certificate copy before the invoice is approved.

What is the unit weight of steel bars?

What is the unit weight of a steel bar, and what does it mean? 

Unit weight means how much a steel bar weighs per metre of its length. It is written as kg/m. For most MSME buyers, this single value is the bridge between both engineering requirements and procurement numbers.

A site team usually talks in diameter and length, like 12mm bars, 12 metres long, or total running metres from a bar bending schedule. A vendor usually quotes in ₹ per kg or ₹ per tonne, then bills by weighbridge. Unit weight connects these two worlds. It helps estimate how many tonnes are needed, compare vendor quotes on the same basis, and check whether deliveries match the purchase order.

Unit weight is often confused with density. Density is a material property, usually taken as 7850 kg/m³ for steel in standard calculations. Unit weight is the output used for buying and planning. It changes with bar diameter, because thicker bars have more steel in every metre.

Why unit weight calculation matters

For MSMEs evaluating vendors and managing multiple sites, unit weight helps in three practical ways:

• It improves cost estimation, because total weight drives the final bill.
• It supports logistics planning, because truckloads and unloading are managed in tonnes.
• It reduces billing disputes, because expected weight can be compared with invoice and weighbridge weight using a simple reconciliation sheet.

How to calculate the unit weight of steel bars?

Most steel bars used in construction are round, so the calculation is based on the steel bar’s circular cross-section. The logic is simple. Find the volume of steel in the bar, then multiply by steel density.

The core formula:

Weight = Volume × Density

• Density of steel (for standard calculations): 7850 kg/m³
• Volume of a round bar: Cross-sectional area × Length
• Area of a circle: πr², where r = D/2

Now, putting it together for a round steel bar:

Weight = (π × D² / 4) × L × 7850 × 10⁻⁶

Here, D is in mm, L is in metres, and the result comes in kg. The 10⁻⁶ factor converts mm² into m².

Steps to calculate the unit weight of steel bars

Let’s look at a simple example to understand how to find the weight of a steel bar.

Step 1: Know the dimensions

Steel TMT bars come in standard diameters like 8 mm, 10 mm, 12 mm, 16 mm, etc.

Here, the diameter is the end-to-end measurement of the circular face of the bar.

In this example, we’ll use:

• Length = 10 m
• Diameter = 12 mm
• Radius = 6 mm or 0.006 m (half the diameter)

Step 2: Calculate the cross-sectional area

Use the formula:

Area = πr²

= 3.1416 × (0.006)²

= 0.000113 m²

Step 3: Find the volume per meter

Volume = Area × Length

= 0.000113 × 10

= 0.00113 m³

Step 4: Calculate the total weight of the bar

Weight = Volume × Density

= 0.00113 × 7850

= 8.87 kg (approx.)

This method is reliable and helps explain the logic to finance and audit teams when questions come up later.

The shortcut used on site, D²/162 (kg/m)

For daily procurement work, most teams use a quick rule:

Unit weight (kg/m) = D²/162

D must be in mm.

For example, we’ll use here diameter as 12mm, then:
12²/162 = 144/162 = 0.889 kg/m

From here, a standard 12 m bar weight becomes:
0.889 × 12 = 10.67 kg

Procurement-friendly use cases

• Convert running metres to tonnes
  Total weight (kg) = Total running metres × Unit weight (kg/m)
  Total tonnes = Total weight ÷ 1000

This is useful when the BBS provides total length, but the vendor quotes in tonnes.

• Convert pieces to kilograms for invoice checks
  Expected weight (kg) = Number of pieces × 12 m bar weight (kg)

This makes GRN and invoice matching faster, especially when multiple diameters arrive in one truck.

Common mistakes that cause wrong estimates

• Using diameter in cm or inches without converting to mm before applying D²/162.
• Assuming every piece is exactly 12 m without checking the supplier’s dispatch practice.
• Mixing diameters in one line item, then comparing invoice weight to a single average number.
• Rounding too early, especially on large orders, where small rounding errors become large kg differences.

Unit weight of steel bars sample with approx. price (Jan 2026)

Based on the formula above, here’s a sample weight chart for steel bars of 12-meter length and 8-meter length.

Price basis used (Jan 2026):

• Rebar, IS 1786 Fe 500D: ₹56,000/tonne (~₹56.0/kg)
• Rebar, Fe 500, IS 1786: ₹50,300/tonne (~₹50.3/kg)

Pricing formula used (indicative): Approx. Price per bar = Bar weight (kg) × Rate (₹/kg)

Indicative unit weight and approx price for 12mm steel bar (common trade length)

Diameter (mm)	Radius (mm)	Unit wt. (kg/m)	Weight per 12m bar (kg)	Approx. price (₹56.0/kg)	Approx. price (₹50.3/kg)
8	4.0	0.395	4.74	265	238
10	5.0	0.617	7.41	415	373
12	6.0	0.889	10.67	598	537
16	8.0	1.580	18.96	1,062	954
20	10.0	2.469	29.63	1,659	1,490
25	12.5	3.858	46.30	2,593	2,329
32	16.0	6.321	75.85	4,248	3,815
36	18.0	8.000	96.00	5,376	4,829

*For reference and information only. Not exact. Please check with your steel manufacturer for actual dimensions and weight. Final landed price changes by brand, grade, city, freight, and GST.

Indicative unit weight and approx. price for 8-metre bars (often used in smaller jobs)

Diameter (mm)	Radius (mm)	Unit wt. (kg/m)	Weight per 8 m bar (kg)	Approx. price @ ₹56.0/kg (₹)	Approx. price @ ₹50.3/kg (₹)
8	4.0	0.395	3.160	177	159
10	5.0	0.617	4.936	276	248
12	6.0	0.889	7.112	398	358
16	8.0	1.580	12.640	708	636
20	10.0	2.469	19.752	1,106	994
25	12.5	3.858	30.864	1,728	1,552
32	16.0	6.321	50.568	2,832	2,544
36	18.0	8.000	64.000	3,584	3,219

*For reference only. Always confirm the exact grade, mill, rolling tolerance, bundle count, and weighbridge weight with the supplier before closing the PO.

Grades and sizes of steel bars as per Indian Standard Code

Given below are the nominal size groups of steel bars and steel wires, and their grades according to the Indian Standard code:

Table 1: Grouping of steel bars based on nominal diameter (IS 1786:2008)

Group	Size
Group I	4 mm, 5 mm, 6 mm
Group II	8 mm, 10 mm, 12 mm, 16 mm, 20 mm, 25 mm, 28 mm, 32 mm
Group III	36 mm, 40 mm, 45 mm, and 50 mm

Table 2: Grouping of steel bars based on strength grade (IS 1786:2008)

Group	Strength grade
Group 1	Fe 415, Fe 415D, Fe 415S
Group 2	Fe 500, Fe 500D, Fe 500S
Group 3	Fe 550, Fe 550D
Group 4	Fe 600
Group 5	Fe 650
Group 6	Fe 700

*Source: https://bis.gov.in/wp-content/uploads/2020/07/PM-IS-1786-JULY-2020-Revised-4.pdf

The weight of steel is generally measured in kilograms or tonnes. Construction projects usually source tonnes of steel bars as raw materials. Measuring the unit weight of steel bars is necessary to determine the load-bearing capacity of pillars, columns, etc.

Common application of steel bars

Steel bars are used to reinforce concrete, so the right bar choice affects not only strength but also execution speed, inspection outcomes, and billing confidence. For MSMEs handling multiple sites, the practical goal is consistency. The same diameter mix, grade specification, and documentation discipline should repeat across orders, so site teams do not improvise on every delivery.

• Buildings (residential and commercial)

In buildings, steel bars are used in foundations, columns, beams, and slabs. Bars take tensile loads that concrete cannot handle well. Procurement teams usually deal with multiple diameters in the same project, so the key is to control the diameter mix and grade on the PO.

Often missed at site is the connection between reinforcement planning and wastage. Cutting and bending loss, lap lengths, and design changes can push consumption higher than the original estimate. A simple buffer policy and weekly reconciliation reduces last-minute emergency buying at higher rates.

• Bridges and flyovers

Bridges and flyovers face repeated traffic loads and exposure to weather. Procurement should focus on two things: the grade specified by the structural design, and traceability. Inspection teams typically ask for certificates, batch or heat identification, and consistent supply from approved sources.

The practical buying risk is mixing grades across lots. It can happen when a supplier substitutes material during shortages. Avoid this by keeping grade and certificate checks part of GRN closure, not an afterthought.

• Roads, pavements, and retaining structures

Steel bars are used in rigid pavements, drains, culverts, and retaining walls where reinforcement is part of the design. These jobs often run on tight timelines and multiple dispatches. For businesses, the real challenge becomes is delivery planning and preventing mismatch between ordered and received quantities.

Short supplies are usually spotted late when bar cutting begins. The best time to catch it is at unloading, by matching pieces and weighbridge weight against the PO.

• Dams and water-retaining structures

Water-retaining structures demand tight control on quality and execution, because cracking and leakage become expensive defects. Hence, procurement teams must stick strictly to the grade and documentation requirements mentioned in project specifications. Apart form it, storage and handling also matter. Even steel bars left exposed to heavy moisture or mud can create avoidable site-level quality concerns.

• Industrial buildings and power plants

Factories, heavy foundations, and equipment bases can involve higher reinforcement density and more complex bar schedules. Steel procurement planning must align with the pouring sequence, not only total tonnage. Smaller, timed dispatches often reduce congestion at site and lower the chance of wrong diameter being issued to the wrong zone.

Often missed in tender planning

Many government and large EPC jobs expect clean records, not only material. Keep a simple audit trail that links the PO to delivery challans, weighbridge slips, and test certificates. This reduces rework during client verification and helps avoid payment holds.

Practical procurement lens

Application	What procurement should confirm	Common avoidable mistake
Buildings	Dia mix and grade on PO, planned dispatch schedule, basic reconciliation	Emergency buying due to under-planned wastage and laps
Bridges/flyovers	Strict grade matching, certificate and traceability discipline	Mixing grades across dispatches, weak certificate checks
Roads/retaining works	Delivery planning and site storage, diameter segregation	Short supply detected late, after cutting starts
Water structures	Spec compliance, controlled handling and storage	Ignoring documentation, then failing inspections
Industrial plants	Sequenced dispatches, correct diameter availability	Wrong diameter issued on site due to poor segregation

Rolling and Mass Tolerance (Why Weight Can Differ)

Steel bars are manufactured with permitted variations in mass per metre. That is why theoretical weight (D²/162) and weighbridge weight can differ slightly. For procurement teams, the right approach is to track variance, not panic on small differences.

Permissible tolerance on nominal mass (IS 1786:2008, Table 2)

(Use as a practical reference for receiving checks.)

Nominal diameter	Typical tolerance band used for checks
Up to and including 10 mm	±7%
Over 10 mm up to and including 16 mm	±5%
Over 16 mm	±3%

Simple on-site verification checklist

• Count pieces by diameter and record bundle tags.
• Match challan, weighbridge slip, and invoice numbers.
• If variance looks high, sample-check 2 to 3 bars per diameter using weight per metre (cut a 1 m sample if required).
• Do not mix diameters in one line item during reconciliation.

Conclusion

Steel bar weight is not only a calculation topic, it is a procurement control topic. Unit weight (kg/m) helps convert drawings and running metres into tonnes, and that directly impacts ordering, transport planning, and budgeting.

The most common issues on projects come from small gaps between estimation and execution. Bars get ordered by pieces, billed by weighbridge weight, and received in mixed diameters. Without a simple reconciliation sheet, shortages or overbilling can slip through unnoticed.

A practical way to stay in control is consistent across projects. That is:

• Use the weight chart for quick planning, apply the D²/162 shortcut for fast checks, and verify deliveries using a PO versus delivery versus invoice table.
• Keep grade and documentation checks always part of GRN closure, not a later audit step.

With these steps in mind, MSME teams can reduce last-minute buying, avoid disputes with suppliers, and maintain cleaner records for client verification and tender work.

Disclaimer: *This article is for information sharing only. The weight calculation process explained is for readers to understand how steel bars are weighted. Dimensions are for reference. Please consult with your steel supplier for exact dimensions, sizes, weight, and other details.

FAQs

How heavy is a 12 mm TMT bar per meter?

A 12 mm tmt bar weighs 0.888 kg per metre (12² ÷ 162).

How many 8 mm TMT bars make one ton?

For 12 m bars, each weighs 4.74 kg. 1,000 kg ÷ 4.74 kg ≈ 211 bars per tonne.

What are the size groups of steel bars under IS 1786?

Group I: 4–6 mm, Group II: 8–32 mm, Group III: 36–50 mm

Which strength grades of TMT bars are available in India?

Grades range from Fe 415 up to Fe 700. (Fe 415 / 500 / 550 / 600 / 650 / 700, with D and S variants).

Is BIS certification compulsory for TMT bars in 2025?

Yes. Under the 2024 Quality‑Control Order, every TMT bar sold must carry a valid BIS mark.

Which TMT grade is best for residential buildings?

Fe 500D is widely preferred; it offers ductility for quake resistance and meets most building codes.

What density of steel should I use for weight calculations?

Use 7,850 kg/m³, the standard density for carbon‑steel bars.

What is the meaning of the unit weight of TMT bar?

The unit weight of a TMT bar is the weight per metre (kg/m) of a single steel rod. Common sizes range from 8 mm to 32 mm, and bars are usually purchased by weight (kg or tons) or number of pieces based on project needs.

What is the formula for steel weight calculation?

Steel weight is calculated using Weight = Volume × Density (7850 kg/m³)

Steel Type	Weight Formula	Example Dimensions	Approx. Weight
TMT Bars	π × r² × L × 7850	L = 12 m, r = 6 mm (0.006 m)	≈ 10.6 kg
Steel Beams	L × W × H × 7850	L = 6 m, W = 0.1 m, H = 0.2 m	942 kg
Steel Sheets	L × W × Thickness × 7850	L = 2 m, W = 1 m, T = 0.002 m	31.4 kg
Steel Pipes/Tubes	π × (R² − r²) × L × 7850	L = 3 m, R = 0.05 m, r = 0.045 m	≈ 20.3 kg

What is the difference between Fe 500 and Fe 500D?

Fe 500D has higher ductility and lower carbon content, making it better for seismic zones and bending applications.