Stainless Steel Weight Calculator

Pipe & tube, plate & sheet, round / square / hex / flat bar — calculate weight in kg and lb using the exact density of your grade (304, 304L, 316, 316L, 201, 430, 2205 & more).

Updated: August 20, 2026 Metric & Imperial units 25+ grades with density lookup Free to use

Quick Reference — Common 304 Stainless Steel Weights

Round Bar Ø20 mm
304 / 304L
2.49 kg/m
Round Bar Ø50 mm
304 / 304L
15.57 kg/m
Pipe 21.3 × 2.77
304 / 304L (1″ Sch 40)
1.28 kg/m
Pipe 48.3 × 3.68
304 / 304L (1½″ Sch 40)
4.09 kg/m
Flat Bar 40 × 5
304 / 304L
1.59 kg/m
Sheet 1000 × 2000 × 1
304 / 304L
15.86 kg

Interactive Weight Calculator

Select a product shape, choose your stainless steel grade (density is filled in automatically — override it if needed), enter dimensions and length, and the total weight, weight per meter, and the formula used are calculated instantly. Results are shown in both metric and imperial units.

Weight = π × wall × (OD − wall) × length × ρ ÷ 1000 (kg, dimensions in mm, length in m)

Weight = π × d² ÷ 4 × length × ρ ÷ 1000 (kg, d in mm, length in m)

Weight = side² × length × ρ ÷ 1000 (kg, side in mm, length in m)

Weight = 2.598 × (across flats)² × length × ρ ÷ 1000 (kg; hex area = 2.598 × s²)

Weight = width × thickness × length × ρ ÷ 1000 (kg, dimensions in mm, length in m)

Weight = width × length × thickness × ρ ÷ 1,000,000 (kg, all dimensions in mm)

Calculated Weight
Enter dimensions above — results update as you type.
Theoretical weight only. Actual weight depends on rolling tolerances and surface finish — always confirm the weight basis with your supplier before invoicing or freight booking.

Weight Formulas Explained

Every stainless steel weight calculation follows one principle: Weight = Cross-Sectional Area × Length × Density. The formulas below assume dimensions in millimetres (mm), length in metres (m), density ρ in g/cm³, and give the result in kilograms (kg).

Round Bar (圆棒)

W (kg/m) = π × d² ÷ 4000 × ρ

Where d = diameter in mm. Example: 304 (ρ 7.93), Ø20 mm → 3.14159 × 400 ÷ 4000 × 7.93 = 2.49 kg/m.

Square Bar

W (kg/m) = a² ÷ 1000 × ρ

Where a = side length in mm. Example: 304, 20 × 20 mm → 400 ÷ 1000 × 7.93 = 3.17 kg/m.

Hex Bar

W (kg/m) = 2.598 × s² ÷ 1000 × ρ

Where s = width across flats in mm (hex area factor = 3√3/2 ≈ 2.598). Example: 304, 20 mm AF → 2.598 × 400 ÷ 1000 × 7.93 = 8.24 kg/m.

Flat Bar

W (kg/m) = w × t ÷ 1000 × ρ

Where w = width and t = thickness in mm. Example: 304, 40 × 5 mm → 200 ÷ 1000 × 7.93 = 1.59 kg/m.

Pipe / Tube

W (kg/m) = π × t × (OD − t) ÷ 1000 × ρ

Where OD = outside diameter and t = wall thickness in mm. Example: 304, OD 21.3 × 2.77 → 3.14159 × 2.77 × 18.53 ÷ 1000 × 7.93 = 1.28 kg/m.

Sheet / Plate

W (kg) = W × L × t × ρ ÷ 1,000,000

Where W, L, t are width, length and thickness all in mm. Example: 304, 1000 × 2000 × 1 mm → 2,000,000 × 7.93 ÷ 1,000,000 = 15.86 kg.

Imperial quick checks: 1 kg = 2.20462 lb · 1 kg/m = 0.67197 lb/ft · 1 kg/m² = 0.2048 lb/ft² · 1 g/cm³ = 0.0361 lb/in³.

Stainless Steel Density by Grade

Density is the key input for any weight calculation. Austenitic grades are the heaviest (7.9–8.0 g/cm³); martensitic and ferritic grades are lighter (≈ 7.7 g/cm³); duplex and precipitation-hardening grades sit at ≈ 7.8 g/cm³. Values are nominal — the mill certificate states the actual measured value for each heat.

Nominal Density of Common Stainless Steel Grades
Grade / UNS Family Density g/cm³ Density kg/m³ Density lb/in³
201, 202 (S20100, S20200)Austenitic7.9379300.286
301, 302, 303 (S30100, S30200, S30300)Austenitic7.9379300.286
304, 304L, 304H (S30400, S30403, S30409)Austenitic7.9379300.286
305 (S30500)Austenitic8.0080000.289
309, 309S (S30900, S30908)Austenitic7.9879800.288
310, 310S (S31000, S31008)Austenitic7.9879800.288
316, 316L, 316H (S31600, S31603, S31609)Austenitic7.9879800.288
316Ti (S31635)Austenitic8.0080000.289
317, 317L (S31700, S31703)Austenitic8.0080000.289
321 (S32100)Austenitic7.9379300.286
347 (S34700)Austenitic8.0080000.289
904L (N08904)Super austenitic7.9579500.287
409 (S40900)Ferritic7.7077000.278
410 (S41000)Martensitic7.7077000.278
420 (S42000)Martensitic7.7077000.278
430 (S43000)Ferritic7.7077000.278
434, 439 (S43400, S43035)Ferritic7.7077000.278
440A / 440B / 440C (S44002–04)Martensitic7.7077000.278
446 (S44600)Ferritic7.5075000.271
2205 Duplex (S32205 / S31803)Duplex7.8078000.282
2507 Super Duplex (S32750)Super duplex7.8078000.282
17-4PH (S17400)Precipitation-hardening7.8078000.282
15-5PH (S15500)Precipitation-hardening7.8078000.282

Density values are nominal per ASTM/EN material datasheets. Some references list 321 at 7.93 and 316Ti at 8.0 g/cm³; always prefer the value on the mill certificate.

Stainless Steel Weight Charts

Two of the most frequently searched reference tables: round bar weight per metre, and the weight of a standard 4 × 8 ft sheet/plate at common thicknesses. Use the calculator above for any other size.

Round Bar Weight per Metre (kg/m) — 304 vs 316
Diameter (mm)304 (ρ 7.93) kg/m316 (ρ 7.98) kg/m304 lb/ft
60.220.230.15
80.400.400.27
100.620.630.42
120.900.900.60
141.221.230.82
161.591.601.07
182.022.031.36
202.492.511.67
253.893.922.62
305.615.643.77
409.9710.036.70
5015.5715.6710.46
6022.4222.5615.07
8039.8640.1126.79
10062.2862.6841.85
Weight of a Standard 4 ft × 8 ft (1219 × 2438 mm) Stainless Steel Sheet / Plate
Thickness304 Weight (kg)316 Weight (kg)304 Weight (lb)
1.0 mm23.5823.7252.0
1.5 mm35.3635.5978.0
2.0 mm47.1547.45104.0
3.0 mm70.7371.17156.0
4.0 mm94.3094.89208.0
5.0 mm117.88118.62260.0
6.0 mm141.45142.34312.0
8.0 mm188.60189.79416.0
10 mm235.75237.24520.0
12 mm282.90284.68624.0
⅛″ (3.175 mm)74.8575.32165.0
¼″ (6.35 mm)149.70150.65330.0
½″ (12.7 mm)299.40301.29660.0

Theoretical weights based on nominal dimensions and density. Per 1 mm of thickness, a 4×8 ft 304 sheet weighs 23.58 kg (52.0 lb); 316 is 0.6% heavier.

Frequently Asked Questions

Quick answers to the questions we are asked most often about stainless steel weight calculation.

How do I calculate the weight of stainless steel?
Weight = Cross-Sectional Area × Length × Density. Compute the cross-sectional area of the shape (π × d²/4 for round bar; π × wall × (OD − wall) for pipe; width × thickness for flat bar and plate), multiply by length in metres and by the grade density in g/cm³ (7.93 for 304/304L, 7.98 for 316/316L), then divide by 1000 to get kg. For sheets where width, length and thickness are all in mm, divide by 1,000,000 instead.
What is the density of 304 stainless steel?
304/304L stainless steel has a density of 7.93 g/cm³ (7930 kg/m³, 0.286 lb/in³). The same value applies to the wider 300-series family — 201, 202, 301, 302, 303 and 321 — while 316/316L is slightly heavier at 7.98 g/cm³.
What is the density of 316 stainless steel?
316/316L stainless steel has a density of 7.98 g/cm³ (7980 kg/m³, 0.288 lb/in³). The extra molybdenum (2–3%) that gives 316 its superior pitting resistance also makes it about 0.6% heavier than 304.
How do I calculate the weight of a stainless steel pipe or tube?
Use: Weight (kg/m) = π × wall × (OD − wall) × ρ ÷ 1000 — OD and wall in mm, ρ in g/cm³. A 304 pipe, OD 21.3 × 2.77 mm, therefore weighs 3.14159 × 2.77 × 18.53 × 7.93 ÷ 1000 ≈ 1.28 kg/m. This works for both seamless and welded pipe, round tube, and pressure tube.
How much does a 4×8 sheet of 304 stainless steel weigh?
A 4 ft × 8 ft (1219 × 2438 mm) 304 sheet weighs 23.6 kg (52.0 lb) per 1 mm of thickness. Common values: 2 mm → 47.2 kg (104 lb), 3 mm → 70.7 kg (156 lb), 6 mm → 141.5 kg (312 lb), ½″ (12.7 mm) → 299 kg (660 lb). For 316, multiply by 1.006.
Why does 316 stainless steel weigh more than 304?
Because 316 contains 2–3% molybdenum, which is denser than the iron, chromium and nickel that dominate both alloys, its density is 7.98 vs 7.93 g/cm³. Identically-dimensioned 316 products are about 0.6% heavier than 304 — small per piece, but meaningful for large tonnage orders and freight.
Is the calculated weight the same as the actual weight?
No. Calculated weight is theoretical weight based on nominal dimensions and nominal density. Actual weight differs because of rolling tolerances (±5–10% on thickness/diameter/wall), heat-to-heat composition variation, surface-finish material removal (pickling, polishing), and pipe wall-tolerance practices. Most mills invoice on theoretical weight; always confirm the weight basis with your supplier.
How do I convert stainless steel weight from kg to lb?
Multiply kg by 2.20462 to get lb. Useful conversions: 1 kg/m = 0.67197 lb/ft; 1 kg/m² = 0.2048 lb/ft²; 1 g/cm³ = 0.0361 lb/in³. A 20 mm 304 round bar at 2.49 kg/m is therefore 1.67 lb/ft.
What is the weight per metre of common stainless steel round bars?
For 304 (ρ 7.93): 10 mm → 0.62 kg/m, 12 mm → 0.90, 16 mm → 1.59, 20 mm → 2.49, 25 mm → 3.89, 30 mm → 5.61, 40 mm → 9.97, 50 mm → 15.57 kg/m. Formula: kg/m = π × d² × ρ ÷ 4000. For 316, multiply by 1.006.
Can I use the same weight formula for pipe and tube?
Yes. The annulus formula works for welded and seamless pipe, round tube and pressure tube regardless of the standard (ASTM A312/A554, EN 10216-5, JIS G3459) because it is purely geometric. For square/rectangular hollow sections, use the true cross-section: (outer W × H) − (inner W × H), then × length × density.
Which stainless steel grade is the heaviest?
The high-nickel and molybdenum-bearing austenitic grades are heaviest: 305, 316Ti, 317/317L and 347 at 8.00 g/cm³, followed by 904L at 7.95. The lightest common grades are the ferritic heat-resistant grade 446 at 7.50 g/cm³ and the martensitic/ferritic grades (410, 420, 430, 440C) at 7.70 g/cm³.

Data Sources & Disclaimer

References

  1. ASTM A480/A480M — General Requirements for Flat-Rolled Stainless Steel (density basis for sheets and plates).
  2. ASTM A312/A312M — Seamless, Welded, and Heavily Cold Worked Austenitic Stainless Steel Pipe.
  3. ASTM A554 — Welded Stainless Steel Mechanical Tubing.
  4. EN 10088-1 — Stainless Steels, Part 1: List of Stainless Steels (density values per grade).
  5. EN 10216-5 — Seamless Steel Tubes for Pressure Purposes — Stainless Steel.
  6. JIS G4304 / G4305 / G4318 — Hot-rolled / cold-rolled stainless plate and bar (weight calculation conventions).
  7. ISO 9001 mill certificates — actual measured density and weight basis per heat.
  8. International Nickel Institute & Euro Inox stainless steel design manuals (density reference data).

Disclaimer

All weights shown are theoretical, calculated from nominal dimensions and nominal grade density. Actual delivered weight may differ due to dimensional tolerances, manufacturing practice, and surface finish. This calculator is provided for estimation, engineering reference, and quotation purposes only — it is not a substitute for the mill certificate, the governing product standard, or professional engineering judgement. Always confirm the weight basis (theoretical vs actual) and applicable tolerances with your supplier before finalizing purchase orders or freight bookings.