When you order aluminum sheet, the size you ask for is usually one of a small set of standard dimensions, and ordering off-standard is where lead time and cost creep in. This page is the aluminum sheet standard sizes and thicknesses — the dimensions that are stocked, and the dividing line between sheet and plate.
Standard sheet sizes
Three metric sizes dominate international supply, plus one imperial size that is the North American default:
| Size | Description | Square metres |
|---|---|---|
| 1,220 × 2,440 mm | 4 ft × 8 ft (North American standard) | 2.98 m² |
| 1,250 × 2,500 mm | Metric standard | 3.13 m² |
| 1,500 × 3,000 mm | Large metric sheet | 4.50 m² |
| 1,000 × 2,000 mm | Small sheet, common in Asia | 2.00 m² |
The 4×8 ft sheet (1,220 × 2,440 mm) is the workhorse in North America; 1,250 × 2,500 mm and 1,500 × 3,000 mm are the metric equivalents that dominate European and Asian supply. Widths generally run 1,000 to 2,650 mm, with 2,000 mm a common practical maximum for wide sheet before you move into plate territory.
The point worth internalizing: the 4×8 sheet is not the same size as the metric sheet. 1,220 × 2,440 mm is about 3% smaller than 1,250 × 2,500 mm, and the difference matters when you are nesting parts or comparing per-sheet prices.
Sheet versus plate: the 6 mm line
The industry divides flat aluminum into sheet (thin) and plate (thick), and the boundary is roughly 6 mm (0.250 inch):
- Sheet: below ~6 mm, rolled and cut to length, with the tolerance table for sheet.
- Plate: 6 mm and above, with a different tolerance table, different handling and often different pricing.
The distinction is not arbitrary — it changes the tolerance, the flatness requirement and the mill route. A "thick sheet" above 6 mm is plate, and it should be specified and priced as plate.
Common stock thicknesses run: 0.5, 0.8, 1.0, 1.2, 1.5, 2.0, 2.5, 3.0, 4.0, 5.0, 6.0 mm for sheet, and then 8, 10, 12, 15, 20, 25, 30, 40, 50 mm and up for plate, with thick plate available past 200 mm for the grades that are stocked that way.
Which grades come in which sizes
Not every grade is stocked in every size. The pattern to expect:
- 1xxx and 3xxx (1050, 1100, 3003, 3004): stocked across the full sheet range, including the thin gauges, because they are the general forming and roofing grades.
- 5xxx (5052, 5083, 5754): strong stocking in sheet and plate, especially 5052, which is the general marine and tank grade. 5083 plate is stocked thick for hull work.
- 6xxx (6061, 6082): 6061 is stocked in sheet and, more commonly, in plate and bar for machining; 6063 is an extrusion grade and rarely appears as flat-rolled sheet.
- 7xxx (7075): stocked in plate and bar, with sheet available in thinner gauges, often alclad for corrosion resistance.
The rule: check stock before you design around a size. A drawing that calls for a 7075 sheet in a size only stocked in 6061 means a mill order and a longer lead time.
Ordering off-standard
Custom sizes are always available — a coil line can cut to length at almost any dimension — but they cost time and money. The two costs to expect:
- Cut-to-length from coil. If the width is standard but the length is not, the sheet is cut from coil, which is fast and cheap.
- A width the mill does not roll. If the width itself is off-standard, the order becomes a mill run, which means minimum quantities and real lead time.
The economical habit is to design parts to nest onto a standard sheet and reserve custom cutting for the dimensions that genuinely need it.
The checksum before ordering
When you write a size on an order, confirm three things and there is rarely a surprise later:
- Sheet or plate — which side of the 6 mm line, because it changes the tolerance and price.
- Which standard size — 4×8 ft (1,220 × 2,440) or metric (1,250 × 2,500 / 1,500 × 3,000), stated in millimeters to remove ambiguity.
- Which grade and temper — because stock coverage varies by grade, and a size stocked in 5052 may not be stocked in 7075.
For the tolerance that goes with each thickness and width band, see the thickness tolerance reference, and for the grade that suits the job, the alloy reference pages. If you have a parts list and want it nested onto standard sheets, send the dimensions — the nesting decision usually pays for itself in material saved.