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A 24x36 poster fits a 36x30 in wall exactly. Find the largest poster that fits your wall, from 8.5x11 to A0, with area, aspect ratio, and diagonal. Enter your wall size to find yours.
Poster sizes run from 8.5x11 in for a small print to A0 at 33.1x46.8 in for the largest standard poster. This chart lists the standard US and A-series sizes with their area, aspect ratio, and diagonal — and it picks the largest poster that fits the wall you enter, in either orientation. This is a size and area reference, not a framing, mounting, or wind-load/engineering chart.
Poster sizes run from 8.5x11 in for a small print to A0 at 33.1x46.8 in for the largest standard poster. The chart below lists the standard US and A-series sizes: the area in square inches and square feet, the aspect ratio (the long side divided by the short side), the diagonal, and what each size is best for. The aspect ratios cluster around 1.33, 1.41, and 1.50 — the three classic poster proportions. A-series sizes are ISO 216. This is a size and area reference, not a framing, mounting, or wind-load/engineering chart.
| Poster size | Area (sq in) | Area (sq ft) | Aspect ratio | Diagonal (in) | Best for |
|---|---|---|---|---|---|
| 8.5x11 | 93.50 | 0.65 | 1.29 | 13.90 | small prints, flyers, desk frames |
| 11x17 | 187.00 | 1.30 | 1.55 | 20.25 | tabloid prints, small posters, menus |
| 12x18 | 216.00 | 1.50 | 1.50 | 21.63 | small posters, art prints, signs |
| 18x24 | 432.00 | 3.00 | 1.33 | 30.00 | standard posters, dorm rooms, offices |
| 20x30 | 600.00 | 4.17 | 1.50 | 36.06 | large posters, galleries, bedrooms |
| 24x36 | 864.00 | 6.00 | 1.50 | 43.27 | the classic movie-poster size, living rooms |
| 27x40 | 1,080.00 | 7.50 | 1.48 | 48.26 | movie posters, home theatres, large walls |
| 30x40 | 1,200.00 | 8.33 | 1.33 | 50.00 | large art prints, statement walls |
| A3 | 193.05 | 1.34 | 1.41 | 20.23 | ISO 216 posters, art prints, portfolios |
| A2 | 386.10 | 2.68 | 1.42 | 28.63 | ISO 216 posters, exhibitions, classrooms |
| A1 | 774.54 | 5.38 | 1.41 | 40.54 | ISO 216 posters, conferences, galleries |
| A0 | 1,549.08 | 10.76 | 1.41 | 57.32 | ISO 216 posters, the largest standard poster |
The pick is the largest poster by area that fits the wall in either orientation — rotation is allowed, and an exact fit counts as fitting. The next size up is the smallest larger poster that does not fit. A wall smaller than 8.5x11 in takes no poster at all, and a wall big enough for A0 has no next size up — the next size up is beyond the chart.
At the default — a 36x30 in wall — the largest poster that fits is 24x36 (864.00 sq in, 6.00 sq ft, aspect 1.50, diag 43.27 in). The next size up, 27x40, does not fit: 40 in is the long side either way. Note the exact fit: 36 in wide is the wall width exactly.
Setup: wall 36 in wide by 30 in tall, poster 24x36 in.
Line 1 — the area. 24 × 36 = 864.00 sq in, and 864 ÷ 144 = 6.00 sq ft.
Line 2 — the aspect ratio. 36 ÷ 24 = 1.50.
Line 3 — the diagonal. √(24² + 36²) = 43.27 in.
Line 4 — the fit. Rotated, 36 in wide fits the 36 in wall exactly and 24 in tall fits the 30 in wall — so 24x36 fits.
Line 5 — the next size up. 27x40 is larger, but 40 in is longer than the 36 in wall even rotated — so 27x40 does not fit. Rounding convention: all figures are computed from unrounded values and rounded only for display — areas to two decimals, aspect ratios and diagonals to two decimals, so a figure worked out from the rounded numbers can differ slightly from the figure shown.
Reverse: a 24x18 in wall takes an 18x24 poster (432.00 sq in, 3.00 sq ft), and the next size up, 20x30, does not fit. A 60x50 in wall takes an A0 poster, and the next size up is beyond the chart. An 8x10 in wall takes no poster at all. Given a poster, the wall it needs is the poster size itself: a 24x36 wants a 28x40 in clear wall with 2 in of clearance on each side for framing.
8.5x11: 93.50 sq in, 0.65 sq ft, aspect 1.29, diag 13.90 in — small prints, flyers, desk frames. 11x17: 187.00 sq in, 1.30 sq ft, aspect 1.55, diag 20.25 in — tabloid prints, small posters, menus. 12x18: 216.00 sq in, 1.50 sq ft, aspect 1.50, diag 21.63 in — small posters, art prints, signs.
18x24: 432.00 sq in, 3.00 sq ft, aspect 1.33, diag 30.00 in — standard posters, dorm rooms, offices. 20x30: 600.00 sq in, 4.17 sq ft, aspect 1.50, diag 36.06 in — large posters, galleries, bedrooms. 24x36: 864.00 sq in, 6.00 sq ft, aspect 1.50, diag 43.27 in — the classic movie-poster size, living rooms.
27x40: 1,080.00 sq in, 7.50 sq ft, aspect 1.48, diag 48.26 in — movie posters, home theatres, large walls. 30x40: 1,200.00 sq in, 8.33 sq ft, aspect 1.33, diag 50.00 in — large art prints, statement walls.
A3: 193.05 sq in, 1.34 sq ft, aspect 1.41, diag 20.23 in. A2: 386.10 sq in, 2.68 sq ft, aspect 1.42, diag 28.63 in. A1: 774.54 sq in, 5.38 sq ft, aspect 1.41, diag 40.54 in. A0: 1,549.08 sq in, 10.76 sq ft, aspect 1.41, diag 57.32 in — the largest standard poster, ISO 216.
Reverse — the other way round: a 24x18 in wall takes an 18x24 poster; a 60x50 in wall takes an A0 poster and the next size up is beyond the chart; an 8x10 in wall takes no poster at all. Extras: a 24x36 poster is 9.24x the area of an 8.5x11 sheet; a 30x40 poster is 12.83x; an A0 poster is 16.57x.
The chart assumes the standard poster sizes above, with the A-series sizes from ISO 216. It assumes you measure the wall width and height in inches, and the poster size by its printed dimensions, width by height. It assumes rotation is allowed: a poster can hang landscape or portrait, whichever fits. It does not know the frame: add 2 in of clearance on each side for framing, so a 24x36 wants a 28x40 in clear wall. It does not score poster material, which changes how a poster hangs and how long it lasts. With a 0 or negative wall size the calculator asks for a real number. Rounding convention: all figures are computed from unrounded values and rounded only for display — areas to two decimals, aspect ratios and diagonals to two decimals, so a figure worked out from the rounded numbers can differ slightly from the figure shown.
| Output | Formula | What it means |
|---|---|---|
| Largest poster that fits | the largest area that fits the wall in either orientation | 24x36 (864.00 sq in, 6.00 sq ft, aspect 1.50, diag 43.27 in). |
| Next size up | the smallest larger area that does not fit | 27x40 (40 in is the long side either way). |
| Poster size | the size you pick | 24x36. |
| Wall with 2 in clearance | poster size + 4 in each way (2 in on each side) | 28.0 in wide × 40.0 in tall. |
| 24x36 vs 8.5x11 area | 864 ÷ 93.5 | 9.24x. |
| 30x40 vs 8.5x11 area | 1,200 ÷ 93.5 | 12.83x. |
| A0 vs 8.5x11 area | 1,549.08 ÷ 93.5 | 16.57x. |
| Wall 24x18 in | same model, 24x18 in wall | Largest 18x24; next up 20x30 does not fit. |
| Wall 60x50 in | same model, 60x50 in wall | Largest A0; next size up beyond the chart. |
| Wall 8x10 in | same model, 8x10 in wall | no poster fits; smallest size 8.5x11 does not fit. |
| 8.5x11 | same model, 8.5x11 poster | Size 8.5x11, area 93.50 sq in, 0.65 sq ft, aspect 1.29, diag 13.90 in. |
| 11x17 | same model, 11x17 poster | Size 11x17, area 187.00 sq in, 1.30 sq ft, aspect 1.55, diag 20.25 in. |
| 12x18 | same model, 12x18 poster | Size 12x18, area 216.00 sq in, 1.50 sq ft, aspect 1.50, diag 21.63 in. |
| 18x24 | same model, 18x24 poster | Size 18x24, area 432.00 sq in, 3.00 sq ft, aspect 1.33, diag 30.00 in. |
| 20x30 | same model, 20x30 poster | Size 20x30, area 600.00 sq in, 4.17 sq ft, aspect 1.50, diag 36.06 in. |
| 24x36 | same model, 24x36 poster | Size 24x36, area 864.00 sq in, 6.00 sq ft, aspect 1.50, diag 43.27 in. |
| 27x40 | same model, 27x40 poster | Size 27x40, area 1,080.00 sq in, 7.50 sq ft, aspect 1.48, diag 48.26 in. |
| 30x40 | same model, 30x40 poster | Size 30x40, area 1,200.00 sq in, 8.33 sq ft, aspect 1.33, diag 50.00 in. |
| A3 | same model, A3 poster | Size A3, area 193.05 sq in, 1.34 sq ft, aspect 1.41, diag 20.23 in. |
| A2 | same model, A2 poster | Size A2, area 386.10 sq in, 2.68 sq ft, aspect 1.42, diag 28.63 in. |
| A1 | same model, A1 poster | Size A1, area 774.54 sq in, 5.38 sq ft, aspect 1.41, diag 40.54 in. |
| A0 | same model, A0 poster | Size A0, area 1,549.08 sq in, 10.76 sq ft, aspect 1.41, diag 57.32 in. |
The figures are exact for the numbers you enter: the area is width times height, the area in square feet is square inches divided by 144, the aspect ratio is the long side divided by the short side, the diagonal is the square root of width squared plus height squared, the pick is the largest poster by area that fits the wall in either orientation, and the next size up is the smallest larger poster that does not fit. What the chart cannot do is know your real wall: check the wall size, because a wall measured to the trim instead of the clear space reads short, and check the frame, because this chart is a size and area reference, not a framing, mounting, or wind-load/engineering chart. It assumes the standard sizes above; some printers make non-standard sizes. For other standard sizes, see flag size chart, table size chart, and helmet size chart.
Bright Side Kit. "Poster Size Chart: Standard Sizes & Dimensions 2026" https://brightoolbox.com/poster-size-chart/ Accessed October 25, 2026.A 24x36 poster, exactly. It is the largest poster that fits a 36x30 in wall, and it fits exactly: 36 in wide is the wall width exactly. A 27x40 is 4 inches too tall — 40 in is the long side either way, so it does not fit even rotated.
6.00 square feet. 24 times 36 is 864.00 square inches, and 864 divided by 144 is 6.00 square feet. The aspect ratio is 1.50 and the diagonal is 43.27 in. A 24x36 poster is 9.24 times the area of an 8.5x11 sheet.
24x36 in at minimum, 28x40 in with clearance. The poster itself needs a 24x36 in wall, and the page recommends 2 in of clearance on each side for framing, so a 24x36 wants a 28x40 in clear wall. The same rule holds for any size: add 4 in each way.
An 18x24 poster. It is the largest that fits a 24x18 in wall, at 432.00 sq in (3.00 sq ft). The next size up, 20x30, does not fit — 30 in is longer than the 24 in wall even rotated.
The ISO 216 paper sizes. A3 is 11.7x16.5 in (193.05 sq in), A2 is 16.5x23.4 in (386.10 sq in), A1 is 23.4x33.1 in (774.54 sq in), and A0 is 33.1x46.8 in (1,549.08 sq in). Each A size is twice the area of the next smaller one, and every A size has the same aspect ratio, about 1.41.
No. This is a size and area reference: which poster fits which wall, and how big each size is. It is not a framing, mounting, or wind-load/engineering chart. For framing, add 2 in of clearance on each side; for mounting outdoors, check the mounting hardware guidance before buying.