SettingsSettings for this calculationUS
The plate's length.
The cut size you are ordering or the piece you are weighing, not the parent sheet it comes out of. Plate is bought by the piece and priced by weight, so this is also the number that decides the invoice — and an offcut you keep is still weight you paid for. For a shaped plate, use the enclosing rectangle and deduct the cut-outs separately; this calculates a rectangle.
The plate's width.
The other cut dimension. Rolled plate has a grain direction from rolling, and while it makes little difference to weight it matters to bending: a plate bent across the rolling direction cracks more readily than one bent along it. If the piece has to be bent, the width you order may not be free to choose.
The plate's thickness.
The nominal thickness the plate is sold as. Mill tolerance means the real thickness is usually slightly over — plate is rolled to a minimum rather than to a mean — so a weight from nominal is a slight under-estimate, which is the useful direction for a lifting plan and the wrong one for a price. Thickness drives weight linearly, so a 12 mm plate ordered where 10 was wanted is 20% heavier before anything else changes.
Plate mass
362.3 lb
They open the calculator with your figures already in it
Steel Plate Mass Calculator: 362 lb — shown in imperial, US market. The link sets both, so the result they see is the one on your screen.
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How this was calculated
Formula source(s)
- Mass = volume × steel density (7850 kg/m³): Length × Width × Thickness × 7850
Inputs used
- Plate Length
- 6.5 ft
- Plate Width
- 3.5 ft
- Thickness
- 0.39 in
What this calculation does not cover
- The 7850 kg/m³ (490 pcf) density sits in the formula as a fixed constant with no grade or alloy field beside it, so a stainless, tool-steel or aluminium sheet of the same three dimensions comes back at the carbon-steel figure.
- Nothing is added for galvanising, paint or mill primer, because one density term multiplied by one volume leaves no layer for a coating to occupy.
- Volume is taken as length × width × thickness right across the sheet, so bolt holes, torch-cut openings, scallops and edge bevels are all still full of steel here — a burned profile lands under this answer by whatever was cut away.
- Thickness is treated as exact and no rolling-tolerance band is carried through the multiplication, and since mass scales linearly with the figure entered, plate delivered a per cent heavy or light shifts this answer by the same per cent.
- One plate is all this counts, as there is no quantity field to tally a lift or a stack, and the entry ranges stop at 12 m long, 4 m wide and 100 mm thick, so anything larger has to be split into pieces the inputs will accept.
Estimated cost — your price
This site holds no price list for this material — local prices vary too much to publish honestly. Enter your supplier's price and the result is costed with it.
Computed in your browser — nothing you enter is uploaded. Presented in US customary units and US trade terminology. Where a formula follows a published standard, that standard and its edition are cited beside it on this page; where none governs, the page says so. Local amendments override model codes — verify against the code in force where you build.
Sources checked 2026-09-05 · in the site-wide review of 2026-09-06 · v1.0.1
Regulatory standards & verification citations1
- Mass = volume × steel density (7850 kg/m³): Length × Width × Thickness × 7850
Cite this page
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