Carbon Steel Plate Weight
Mass per square metre for carbon steel plate at 7,850 kg/m³ (ASTM A36 / AISI 1018 / EN 10025 S275). Plate is sold by area, so every figure here is per square metre rather than per metre of length.
At the reference dimensions (w = 1000 mm, t = 10 mm) this section has a cross-sectional area of 10,000.0 mm², giving 78.50 kg/m² (16.08 lb/ft²). This is the baseline density, so the figures here are what a steel weight chart shows.
Plate — formula and derivation
Area of a plate
A = w · t
A = w × t. For plate the useful output is mass per unit area: m″ = t × ρ
Worked through with the default dimensions:
A = w × tA = 1000 × 10A = 10000.0 mm²Per square metre: 10 mm × 1 m² = 0.0100 m³/m²
- w
- Width
- t
- Thickness
Weight follows from the area with no further geometry: m = A × 10⁻⁶ × ρ, where A is in mm², ρ in kg/m³ and m in kg/m. At 7,850 kg/m³ that is 78.5000 kg/m for the reference size above.
Carbon steel plate — size series
| Width | Cross-section | Mass / length | Mass / area |
|---|---|---|---|
| 0.5 mm | 500.00 mm² · 0.7750 in² | 3.925 kg/m · 2.637 lb/ft | 3.93 kg/m² · 0.80 lb/ft² |
| 0.8 mm | 800.00 mm² · 1.2400 in² | 6.280 kg/m · 4.220 lb/ft | 6.28 kg/m² · 1.29 lb/ft² |
| 1.0 mm | 1,000.00 mm² · 1.5500 in² | 7.850 kg/m · 5.275 lb/ft | 7.85 kg/m² · 1.61 lb/ft² |
| 1.2 mm | 1,200.00 mm² · 1.8600 in² | 9.420 kg/m · 6.330 lb/ft | 9.42 kg/m² · 1.93 lb/ft² |
| 1.5 mm | 1,500.00 mm² · 2.3250 in² | 11.775 kg/m · 7.912 lb/ft | 11.78 kg/m² · 2.41 lb/ft² |
| 2.0 mm | 2,000.00 mm² · 3.1000 in² | 15.700 kg/m · 10.550 lb/ft | 15.70 kg/m² · 3.22 lb/ft² |
| 3.0 mm | 3,000.00 mm² · 4.6500 in² | 23.550 kg/m · 15.825 lb/ft | 23.55 kg/m² · 4.82 lb/ft² |
| 4.0 mm | 4,000.00 mm² · 6.2000 in² | 31.400 kg/m · 21.100 lb/ft | 31.40 kg/m² · 6.43 lb/ft² |
| 5.0 mm | 5,000.00 mm² · 7.7500 in² | 39.250 kg/m · 26.375 lb/ft | 39.25 kg/m² · 8.04 lb/ft² |
| 6.0 mm | 6,000.00 mm² · 9.3000 in² | 47.100 kg/m · 31.650 lb/ft | 47.10 kg/m² · 9.65 lb/ft² |
| 8.0 mm | 8,000.00 mm² · 12.4000 in² | 62.800 kg/m · 42.200 lb/ft | 62.80 kg/m² · 12.86 lb/ft² |
| 10 mm | 10,000.00 mm² · 15.5000 in² | 78.500 kg/m · 52.750 lb/ft | 78.50 kg/m² · 16.08 lb/ft² |
| 12 mm | 12,000.00 mm² · 18.6000 in² | 94.200 kg/m · 63.299 lb/ft | 94.20 kg/m² · 19.29 lb/ft² |
| 16 mm | 16,000.00 mm² · 24.8000 in² | 125.600 kg/m · 84.399 lb/ft | 125.60 kg/m² · 25.72 lb/ft² |
| 20 mm | 20,000.00 mm² · 31.0001 in² | 157.000 kg/m · 105.499 lb/ft | 157.00 kg/m² · 32.16 lb/ft² |
| 25 mm | 25,000.00 mm² · 38.7501 in² | 196.250 kg/m · 131.874 lb/ft | 196.25 kg/m² · 40.20 lb/ft² |
| 30 mm | 30,000.00 mm² · 46.5001 in² | 235.500 kg/m · 158.249 lb/ft | 235.50 kg/m² · 48.23 lb/ft² |
| 40 mm | 40,000.00 mm² · 62.0001 in² | 314.000 kg/m · 210.998 lb/ft | 314.00 kg/m² · 64.31 lb/ft² |
| 50 mm | 50,000.00 mm² · 77.5002 in² | 392.500 kg/m · 263.748 lb/ft | 392.50 kg/m² · 80.39 lb/ft² |
| 60 mm | 60,000.00 mm² · 93.0002 in² | 471.000 kg/m · 316.497 lb/ft | 471.00 kg/m² · 96.47 lb/ft² |
Computed for Carbon steel at 7850 kg/m³ (0.2836 lb/in³). ASTM A36 / AISI 1018 / EN 10025 S275.
Each row is one nominal size. The thickness column drives everything: mass per square metre is thickness × density, so it scales in a straight line.
Imperial sizes
Plate is also bought in inch sizes. The conversions below are exact (1 in = 25.4 mm by definition), so the metric equivalents are the true millimetre dimensions rather than a rounded nominal figure.
| Stock size | Metric equivalent mm | Cross-section | Mass per unit area |
|---|---|---|---|
| 3/16 in | 4.76 | 4,762.50 mm² · 7.3819 in² | 37.39 kg/m² · 7.66 lb/ft² |
| 1/4 in | 6.35 | 6,350.00 mm² · 9.8425 in² | 49.85 kg/m² · 10.21 lb/ft² |
| 5/16 in | 7.94 | 7,937.50 mm² · 12.3031 in² | 62.31 kg/m² · 12.76 lb/ft² |
| 3/8 in | 9.52 | 9,525.00 mm² · 14.7638 in² | 74.77 kg/m² · 15.31 lb/ft² |
| 1/2 in | 12.70 | 12,700.00 mm² · 19.6850 in² | 99.69 kg/m² · 20.42 lb/ft² |
| 5/8 in | 15.88 | 15,875.00 mm² · 24.6063 in² | 124.62 kg/m² · 25.52 lb/ft² |
| 3/4 in | 19.05 | 19,050.00 mm² · 29.5276 in² | 149.54 kg/m² · 30.63 lb/ft² |
| 1 in | 25.40 | 25,400.00 mm² · 39.3701 in² | 199.39 kg/m² · 40.84 lb/ft² |
| 1-1/4 in | 31.75 | 31,750.00 mm² · 49.2126 in² | 249.24 kg/m² · 51.05 lb/ft² |
| 1-1/2 in | 38.10 | 38,100.00 mm² · 59.0551 in² | 299.08 kg/m² · 61.26 lb/ft² |
| 2 in | 50.80 | 50,800.00 mm² · 78.7402 in² | 398.78 kg/m² · 81.68 lb/ft² |
Stock sizes in inches, converted exactly at 25.4 mm per inch. Material: Carbon Steel at 7850 kg/m³.
The same plate in every material
Geometry is fixed and only density changes, so this table is the whole material-selection question in one view. Carbon Steel is highlighted. The percentage column is against carbon steel, which is the figure most quotations are built on.
| Material | Density kg/m³ | lb/in³ | Mass / length kg/m | lb/ft | vs carbon steel |
|---|---|---|---|---|---|
| Carbon Steel | 7,850 | 0.2836 | 78.500 | 52.750 | +0.0 % |
| Stainless Steel 304 | 8,000 | 0.2890 | 80.000 | 53.758 | +1.9 % |
| Stainless Steel 316 | 8,000 | 0.2890 | 80.000 | 53.758 | +1.9 % |
| Stainless Steel 316L | 8,000 | 0.2890 | 80.000 | 53.758 | +1.9 % |
| Stainless Steel 430 | 7,700 | 0.2782 | 77.000 | 51.742 | -1.9 % |
| Aluminum 6061-T6 | 2,700 | 0.0975 | 27.000 | 18.143 | -65.6 % |
| Aluminum 5052-H32 | 2,680 | 0.0968 | 26.800 | 18.009 | -65.9 % |
| Aluminum 7075-T6 | 2,810 | 0.1015 | 28.100 | 18.882 | -64.2 % |
| Copper C11000 | 8,940 | 0.3230 | 89.400 | 60.074 | +13.9 % |
| Brass C36000 | 8,500 | 0.3071 | 85.000 | 57.117 | +8.3 % |
| Bronze C93200 | 8,800 | 0.3179 | 88.000 | 59.133 | +12.1 % |
| Titanium Grade 2 | 4,510 | 0.1629 | 45.100 | 30.306 | -42.5 % |
| Gray Cast Iron | 7,200 | 0.2601 | 72.000 | 48.382 | -8.3 % |
| Lead | 11,340 | 0.4097 | 113.400 | 76.201 | +44.5 % |
| Rigid PVC (Type I) | 1,400 | 0.0506 | 14.000 | 9.408 | -82.2 % |
| HDPE (PE 100) | 960 | 0.0347 | 9.600 | 6.451 | -87.8 % |
Same geometry throughout, so the only variable is density. Carbon steel is highlighted as the baseline.
A note on using this table for costing: mass is not price. Aluminium is roughly a third of steel's mass here, but per kilogram it costs several times more, so a straight swap rarely saves money — what it buys is reduced load on a structure or a vehicle.
About carbon steel
The baseline against which every other metal is compared. Mild and medium carbon steels sit at 7,850 kg/m³ across the usual structural and free-machining grades: A36 plate, 1018 shaft, S275JR section. Carbon content moves density so little over the 0.05–0.60 % range that one figure covers the family, which is why mill weight tables for "steel" almost always assume 7,850 kg/m³ (0.2836 lb/in³). Use this entry when the drawing says "steel" and no grade is called out.
- Density
- 7,850 kg/m³ = 0.2836 lb/in³ · 1.0000× carbon steel · typical spread ±1 %
- Specification
- ASTM A36 / AISI 1018 / EN 10025 S275
- Equivalents
- AISI 1018 · EN 1.0401 · JIS SS400 · GB Q235
- Typical uses
- Structural sections · Plate and bar stock · Fabricated weldments · Shafts and pins
Unprotected carbon steel corrodes at roughly 0.1 mm/year in a mild inland atmosphere and far faster in coastal or chemical service, so a corrosion allowance changes the mass you should order — not this density.
About plate
Plate is the one product where the customer usually wants mass per unit area rather than per unit length, because plate is priced and handled by the square metre. Reducing thickness by a fraction of a millimetre has an outsized commercial effect: stepping a 6 mm floor plate down to 5 mm removes 16.7 % of the steel on a job that may be measured in thousands of square metres. That is also exactly why plate thickness tolerances are specified separately from the nominal value — a permitted negative tolerance on a nominally 6 mm plate is real money at scale.
Specified as thickness × width × length, plus the tolerance class and whether the pattern is plain, chequer or floor plate.
Download this data
Carbon steel plate — CSV
Both buttons below read the tables rendered on this page, so the file matches what you are looking at. The full catalogue — all 16 materials across all 10 sections — is on the downloads page.
Fields are quoted per RFC 4180, with a UTF-8 byte-order mark so Excel reads the mm² and · characters correctly. Blank lines separate the weight matrix from the area matrix.
Frequently asked questions
How much does carbon steel plate weigh?
At the reference thickness of 1000 mm, carbon steel plate weighs 7,850.00 kg/m², which is 1,607.81 lb/ft². Weight per unit area is thickness multiplied by density, so it scales in a straight line: halve the thickness and you halve the weight.
How is the weight of plate calculated?
Weight is cross-sectional area × length × density. For this shape the area is A = w · t. At the reference dimensions that gives 10,000.0 mm², and multiplying by carbon steel's density of 7,850 kg/m³ gives 78.500 kg/m. Nothing is looked up in a table — which is why a non-standard size is calculated just as accurately as a standard one.
Why does carbon steel weigh more or less than steel?
It is the 7,850 kg/m³ baseline that every other figure on this site is measured against. Density is the only variable: the cross-sectional area depends purely on geometry, so a plate of the same dimensions has the same area in every material and the mass simply scales with density. In this case the ratio is 1.0000× carbon steel.
What is the cross-sectional area of a plate?
The area depends only on the dimensions, not on the material, so it is identical whichever material you select: at the reference dimensions it is 10,000.0 mm² (15.5000 in²). That is the number you would enter into a stress or deflection calculation, and it is why changing material on this page never changes the area column.
Does a carbon steel plate weigh the same as a carbon steel part of a different shape?
No, and the difference is larger than most people expect. At equal nominal size, a square bar is 27.3 % heavier than a round bar, and a hollow section is typically 60–80 % lighter than the solid bar it replaces. Weight follows area, and area changes faster than dimensions do — which is exactly why this needs calculating rather than estimating.
Other materials, same plate
The same geometry in every material, so the only variable is density.
- SS 304 plate — 8000 kg/m³
- SS 316 plate — 8000 kg/m³
- AL 6061 plate — 2700 kg/m³
- Copper plate — 8940 kg/m³
- Brass plate — 8500 kg/m³
- HDPE plate — 960 kg/m³
- PVC plate — 1400 kg/m³
- AL 5052 plate — 2680 kg/m³
Other Carbon steel sections
The same density applied to every shape the site covers.
- Carbon steel round bar — A = π/4 · d²
- Carbon steel square bar — A = a²
- Carbon steel hexagonal bar — A = (√3/2) · AF² ≈ 0.8660 · AF²
- Carbon steel flat bar — A = w · t
- Carbon steel round tube — A = π/4 · (D² − d²), d = D − 2t
- Carbon steel square tube — A = a² − (a − 2t)²
Reference data and tools
- Metal weight overview — how the calculation works
- All 16 materials — densities and specifications
- All 10 sections — formulas and size series
- Density chart — lightest to heaviest
- Metal weight calculator — any size, any material
- All calculators — metal weight and pipe weight
- Download the data — CSV, generated from the same source
- Cross-reference tables — DN / NPS / material equivalents
- Methodology and sources — where every number comes from
Plate area from A = w · t. Mass computed as area × length × density at 7,850 kg/m³ (ASTM A36 / AISI 1018 / EN 10025 S275). No weight on this page is copied from a published table — which is why figures can differ in the last significant digit from a mill's chart calculated at a nominal density.
- Elementary plane geometry. The circle, polygon and hollow-section area formulas.
- ASTM material specifications for each grade named in the material entry (A36, A240/A276, B209/B211/B221, B152/B16/B505, B265/B348, A48, B29, D1784, D3350).
- BIPM / NIST definitional constants: international inch = 25.4 mm, foot = 0.3048 m, pound = 0.45359237 kg.
Dataset version 2026.09.1 · dimensions last verified against source 2026-09-21. Found an error? Report it — corrections are issued with a version bump.