You are estimating shipping costs for stainless steel pipes. The freight company asks for the total weight. You have the dimensions but need to calculate the weight per meter.

The weight of a stainless steel pipe is calculated using the formula: Weight (kg/m) = (OD - t) × t × 0.0250, where OD is outside diameter in mm and t is wall thickness in mm. For 304 stainless steel¹, density is 7.93 g/cm³; for 316, it is 8.00 g/cm³. The constant 0.0250 works for both grades.

I have used this formula thousands of times for customer quotes. A customer in the UAE needed weight for 2-inch Sch 40S pipe. A customer in the US needed weight for a custom size. Let me walk you through the calculations.

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How much does 304 stainless weigh?

304 stainless steel¹ has a density of 7.93 g/cm³ (0.286 lb/in³). A 1-inch Schedule 40S pipe (33.4mm OD × 3.38mm wall) weighs 2.54 kg per meter (1.71 lb per foot). A 1m × 1m × 2mm sheet weighs about 15.9 kg.

The density of 304 stainless steel²l](https://www.azom.com/article.aspx?ArticleID=2867)[^1] is 7.93 g/cm³, which is slightly less than 316 (8.00 g/cm³) but more than carbon steel (7.85 g/cm³). For quick calculations, use 8.0 g/cm³ or 0.29 lb/in³.

304 Stainless Steel Density

Let me provide density and weight information for 304 stainless steel¹.

Density Values

Material	Density (g/cm³)	Density (lb/in³)
304 stainless	7.93	0.286
316 stainless	8.00	0.289
Carbon steel	7.85	0.284

Quick Weight References (304)

Shape	Dimensions	Weight
Pipe (1", Sch 40S)	1m length	2.54 kg
Pipe (2", Sch 40S)	1m length	5.44 kg
Sheet (1m × 2m × 2mm)	2 m²	31.7 kg
Round bar (20mm dia)	1m length	2.47 kg

My Experience
For a customer ordering 100 meters of 1-inch Sch 40S 304 pipe, the total weight was 254 kg (2.54 kg/m × 100 m).

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What is the rate of SS 304 square pipe¹ per kg?

The rate for SS 304 square pipe¹ is typically $3.50-5.00 per kg for welded pipe, depending on size, thickness, quantity, and market conditions.

To calculate the total cost of a square pipe, first calculate the weight per meter using the formula: Weight (kg/m) = (Perimeter - 4×t) × t × 0.0250 for metric, or use the simplified formula for square pipe: Weight (kg/m) = (W × 4 - 4t) × t × 0.0250, where W is the side length and t is thickness in mm. Then multiply by length and price per kg.

%[alt ss 304 square pipe weight calculation](https://placehold.co/600x400 "304 Square Pipe Weight")

Square Pipe Weight Formula²

Let me provide the formula and example for square pipe.

Formula for Square Pipe (Metric)

Weight (kg/m) = (Side A (mm) + Side B (mm)) × 2 × t (mm) × Density (g/cm³) / 1000

Or simplified for 304 (density 7.93):
Weight (kg/m) = (A + B) × 2 × t × 0.00793

For square pipe (A = B = W):
Weight (kg/m) = W × 4 × t × 0.00793

Example: 304 Square Pipe 40mm × 40mm × 2mm thick

Step	Calculation	Result
1	Perimeter	40 × 4 = 160 mm
2	Perimeter × thickness	160 × 2 = 320
3	× density factor	320 × 0.00793 = 2.54 kg/m

Quick Reference: 304 Square Pipe Weight (kg/m)

Size (mm)	Thickness (mm)	Weight (kg/m)
20×20	1.5	0.95
20×20	2.0	1.27
25×25	2.0	1.59
40×40	2.0	2.54
50×50	2.0	3.17
50×50	3.0	4.76

My Experience
For a customer ordering 50m of 40×40×2mm 304 square pipe, the weight was 50 × 2.54 = 127 kg. At $4.00 per kg, the material cost was $508.

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How do you calculate the weight of MS pipe in KG?

For MS (carbon steel) pipe, the formula is: Weight (kg/m) = (OD - t) × t × 0.02466, where OD is outside diameter in mm and t is wall thickness in mm. The constant 0.02466 is based on carbon steel density¹ (7.85 g/cm³).

For stainless steel (304), use 0.0250. For 316, use 0.0252. For MS pipe, use 0.02466. Example: 2-inch MS pipe (OD 60.3mm, t 3.91mm) weighs (60.3 - 3.91) × 3.91 × 0.02466 = 5.44 kg/m.

MS Pipe Weight Formula

Let me provide the formula and example for MS pipe.

Formula for MS Pipe (Carbon Steel)

Weight (kg/m) = (OD - t) × t × 0.02466

Where:

• OD = outside diameter (mm)
• t = wall thickness (mm)
• 0.02466 = constant for carbon steel density¹ (7.85 g/cm³)

Example: 3-inch MS Pipe (OD 88.9mm, t 5.49mm)

Step	Calculation	Result
1	OD - t	88.9 - 5.49 = 83.41
2	× t	83.41 × 5.49 = 457.9
3	× 0.02466	457.9 × 0.02466 = 11.29 kg/m

Comparison: MS vs Stainless Steel Pipe

Material	Constant	2" Sch 40 Pipe Weight
MS (carbon)	0.02466	5.44 kg/m
304 stainless	0.0250	5.51 kg/m
316 stainless	0.0252	5.56 kg/m

Quick Reference: MS Pipe Weight (kg/m)

Nominal Size	OD (mm)	Sch 40 Wall (mm)	Weight (kg/m)
1/2"	21.3	2.77	1.27
1"	33.4	3.38	2.50
2"	60.3	3.91	5.44
3"	88.9	5.49	11.29
4"	114.3	6.02	16.07

My Experience
For a water line project using MS pipe, we calculated the total weight using 0.02466 constant. The customer used the weight for freight estimation.

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How to calculate weight in kg?

To calculate weight in kg for any steel product, use: Weight (kg) = Volume (cm³) × Density (g/cm³) ÷ 1000¹s://niftyalloys.com/blogs/density-of-steel)² ÷ 1000. For flat sheets: Weight = Length (m) × Width (m) × Thickness (mm) × Density. For round bars: Weight = π × (D²/4) × Length × Density. For pipes: Weight = (OD² - ID²) × π/4 × Length × Density.

Always use consistent units. For metric, convert all dimensions to meters (for volume in m³) or centimeters (for volume in cm³). For steel, density is 7.85-8.00 g/cm³ (7,850-8,000 kg/m³).

General Weight Calculation Formulas

Let me provide formulas for common steel shapes.

Formula Summary Table

Shape	Formula (Metric)	Units
Flat sheet	L × W × T × ρ	L,W=m; T=mm; ρ=7.85-8.00
Round bar	π × (D²/4) × L × ρ	D,m; L,m; ρ=kg/m³
Pipe (OD, t)	π × (OD² - ID²)/4 × L × ρ	OD,ID,m; L,m; ρ=kg/m³
Square bar	S² × L × ρ	S,m; L,m; ρ=kg/m³

Simplified Formulas for Common Use

Shape	Simplified Formula (Metric)	Density
Flat sheet (kg)	L(m) × W(m) × T(mm) × 7.85	Carbon steel
Flat sheet (kg)	L(m) × W(m) × T(mm) × 7.93	304 stainless
Round bar (kg/m)	D²(mm) × 0.00617	Carbon steel
Round bar (kg/m)	D²(mm) × 0.00623	304 stainless
Pipe (kg/m)	(OD - t) × t × 0.02466	Carbon steel
Pipe (kg/m)	(OD - t) × t × 0.0250	304 stainless

Step-by-Step Example: 304 Round Bar, 50mm dia, 2m length

Step	Calculation	Result
1	Area (m²)	π × (0.05²/4) = 0.00196 m²
2	Volume (m³)	0.00196 × 2 = 0.00392 m³
3	Weight (kg)	0.00392 × 7,930 = 31.1 kg

Simplified check: D² × 0.00623 × L = 50² × 0.00623 × 2 = 31.15 kg.

My Experience
I keep a spreadsheet with these formulas. For a quick quote, I use the simplified formulas.

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Conclusion

304 stainless steel pipe weight¹: (OD - t) × t × 0.0250 kg/m. MS pipe²: (OD - t) × t × 0.02466 kg/m. Square pipe: add all sides × t × 0.00793. Use volume × density for any shape.

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