Quick answer
Steel plate mass = length × width × thickness × 7,850 kg/m³. A plate 2,000 × 1,000 × 10 mm weighs 157 kg, since 2 × 1 × 0.01 m³ is 0.02 m³.
Enter length, width, thickness and one unit for all three. The calculator returns the weight in kilograms and pounds.
Related tools: Pipe Weight Calculator: Weight of a hollow round pipe from its outside diameter, wall thickness and length. Glass Weight Calculator: Weight of a glass pane from its dimensions. Gold Weight Calculator: Mass of pure gold from its volume.
How to use the Steel Plate Weight Calculator
- Enter length (above 0).
- Enter width (above 0).
- Enter thickness (above 0).
- Choose unit for all three: Millimeters and Inches.
- Press Calculate to see the result, and use Reset to start again.
| Input | What to enter | Allowed values |
|---|---|---|
| Length | A number | > 0 |
| Width | A number | > 0 |
| Thickness | A number | > 0 |
| Unit for all three | Choose one: Millimeters; Inches | Starts at Millimeters |
Formula and method
Formula
mass = length × width × thickness × 7,850 kg/m³
IEEE-754 double precision; shown to the decimals indicated.
Uses 7,850 kg/m³ (490 lb/ft³), the usual design density of carbon steel. Plan geometry only; confirm quantities with your supplier and local code before ordering.
Worked examples
These examples are verified: each one is an automated test case that the live calculator must reproduce exactly.
Example 1
Inputs: Length = 2; Width = 1; Thickness = 10; Unit for all three = Millimeters.
| Result | Value |
|---|---|
| Plate weight | 0 kg |
| In pounds | 0 |
Example 2
Inputs: Length = 48; Width = 24; Thickness = 0.25; Unit for all three = Inches.
| Result | Value |
|---|---|
| Plate weight | 37.05 kg |
| In pounds | 81.68 |
The first line is the headline result (plate weight). Below it the steel Plate Weight Calculator lists in pounds, which describe the same case from other angles. IEEE-754 double precision; shown to the decimals indicated.
Use one unit
The three dimensions share one unit. An example entered as 2, 1 and 10 with the unit set to millimetres describes a 2 mm piece and rounds to 0 kg, which shows why choosing the unit matters. Pick metres for large plates or millimetres for all three.
Rule of thumb
Steel weighs about 7.85 kg per square metre per millimetre of thickness: a 10 mm plate is 78.5 kg/m². Mill tolerances change real plate weights by a few percent.
How the result changes with length
Holding every other input at the first worked example, this table changes only length. It shows how sensitive the answer is to that one value; each row was produced by running this calculator.
| Length | Plate weight | In pounds |
|---|---|---|
| 1 | 0 kg | 0 |
| 2 | 0 kg | 0 |
| 4 | 0 kg | 0 |
| 8 | 0 kg | 0 |
What happens with invalid input
These messages are produced by the calculator itself, so you know what to fix.
- Length: entering "0" shows "Length must be greater than 0." beside that field and no result.
- Thickness: entering "0" shows "Thickness must be greater than 0." beside that field and no result.
Choosing between the Steel Plate Weight Calculator and similar calculators
Each row shows what a related calculator on this site asks for and what it returns, so you can pick the one that matches your question.
| Calculator | You enter | It returns |
|---|---|---|
| [Pipe Weight Calculator](/construction/pipe-weight/) | outside diameter, wall thickness and length | Pipe weight |
| [Glass Weight Calculator](/construction/glass-weight/) | length, width and thickness | Glass weight |
| [Gold Weight Calculator](/construction/gold-weight/) | volume and unit | Mass |
| [Metal Weight Calculator](/construction/metal-weight-calculator/) | material, shape and dimension A | Weight |
| [Rebar Weight Calculator](/construction/rebar-weight-calculator/) | bar size, length of each bar and number of bars | Total weight |
Background: construction estimates
Material quantities are geometry plus a margin. Calculate the exact volume or area, add an allowance for waste, spillage, cuts and uneven ground (calculator pages commonly mention 5 to 10 percent, a rule of thumb that varies by material and job) and round up to whole units. One cubic yard is exactly 27 cubic feet.
Suppliers often have minimum order sizes and may charge for small loads, so confirm quantities, product yields and local code with your supplier or a qualified estimator before ordering.
Assumptions and limitations
- Mill tolerances change real plate weight
Quantities are estimates. Add allowances for waste and site conditions, and follow local codes and a qualified professional's instructions for structural or safety-critical work.
If a required value is empty, not a number, or outside its allowed range, the form marks that field with a message and shows no result instead of a misleading number. The automated checks deliberately try invalid entries for length and thickness to confirm this.
Frequently asked questions
How heavy is 1 m² of 10 mm steel?
One square metre of 10 mm steel plate weighs about 78.5 kg.
Does stainless weigh the same?
Slightly more, about 8,000 kg/m³.
Can I weigh other metals?
Use the Metal Weight calculator.
What does the Steel Plate Weight Calculator calculate?
Weight of a carbon steel plate from its dimensions. It returns Plate weight and In pounds.
What formula does the Steel Plate Weight Calculator use?
mass = length × width × thickness × 7,850 kg/m³. Uses 7,850 kg/m³ (490 lb/ft³), the usual design density of carbon steel.
What do I need to enter in the steel Plate Weight Calculator?
You enter Length, Width, Thickness and Unit for all three.
How is the result rounded or limited?
IEEE-754 double precision; shown to the decimals indicated. Mill tolerances change real plate weight.
What does the “Unit for all three” option change?
It sets how the steel Plate Weight is worked out. The choices are Millimeters and Inches.
What is an example of a steel Plate Weight result?
With length 2, width 1, thickness 10 and unit for all three Millimeters, the plate weight is 0 kg.
Where does the method come from?
The method follows: AISC Steel Construction Manual: density of steel 490 lb/ft³ (≈7,850 kg/m³).
Can I rely on this calculator for a decision?
Quantities are estimates. Add allowances for waste and site conditions, and follow local codes and a qualified professional's instructions for structural or safety-critical work. For this calculator in particular: Mill tolerances change real plate weight.
Related calculators
- Pipe Weight Calculator — Weight of a hollow round pipe from its outside diameter, wall thickness and length.
- Glass Weight Calculator — Weight of a glass pane from its dimensions.
- Gold Weight Calculator — Mass of pure gold from its volume.
- Metal Weight Calculator — Weight of a plate, round bar or square bar in common metals.
- Rebar Weight Calculator — Weight of reinforcing bar by size and length.
- Money Weight Calculator — Weight of an amount of US bills or coins.
Sources
- AISC Steel Construction Manual: density of steel 490 lb/ft³ (≈7,850 kg/m³)
Content last reviewed 2026-11-04. Formulas and worked examples are checked by automated tests against independently computed values.