20 × 28 frame size
20×28 is a 5:7 rectangle. It shares proportions with a 5×7 photo, but it is two inches shorter than a 20×30 poster of the same width.
Artwork is the full sheet. Nominal frame size is the stated insert reference. The visible opening is the area left after the frame lip or mat covers the edges. Actual frames, mats, rabbets and listed openings vary by manufacturer; these dimensions do not guarantee fit, preservation, hanging safety, load capacity or compatibility.
20 × 28 inches in cm, mm and both orientations
| Measurement | Portrait / listed order | Landscape / reversed order |
|---|---|---|
| Inches | 20 × 28 | 28 × 20 |
| Centimeters | 50.8 × 71.12 | 71.12 × 50.8 |
| Millimeters | 508 × 711.2 | 711.2 × 508 |
| Aspect ratio | 5:7 | 7:5 |
Swapping width and height changes portrait to landscape without changing area. Product features determine which orientations a particular frame supports. A matching ratio preserves shape when scaling an image; it does not make different physical sheet sizes interchangeable.
Without a mat: start with the full 20 × 28 sheet
Compare a frame described for a 20 × 28-inch insert. Measure any printed paper margin as part of that sheet. Do not subtract the front lip from the artwork dimensions unless the supplier explicitly asks for a visible-window measurement. The back opening, depth and clearance must come from the specific product; no universal rabbet allowance is assumed here.
Why a 20×30 frame is not the same label
A 20×28 sheet is nominally 2 inches shorter than a 20×30 opening. A mat designed around those exact rectangles would have very little board beyond the sheet on the sides. That is a reason to check a supplier’s practical window and board constraints, not to infer that the two labels are interchangeable. The larger boards below make the dimension differences easier to compare.
Scaling a 5×7 image to 20×28
Multiply each side by four to keep the 5:7 composition. Scaling a 2:3 image to fill the same target instead crops some of its longer dimension. If a print service adds a margin around the image, measure the final sheet; a 20×28 image with extra paper is no longer a 20×28 physical insert.
Equal borders versus a taller surround
A 24×32 board adds 4 inches in both directions to the artwork, producing equal 2.125-inch borders with the example overlap. A 24×36 board keeps those side borders and increases the top/bottom borders to 4.125 inches. The difference is visible in composition even though both board widths are 24 inches.
With a mat around a full 20 × 28 print
These centered examples use ⅛ inch overlap on each artwork edge, producing a 19.75 × 27.75-inch window. This is an editable illustration, not a prescribed cut. Board sizes are comparison scenarios, including possible custom dimensions; stock availability is not asserted.
| Outer board / nominal frame (in) | Window (in) | Left / right border (in) | Top / bottom border (in) |
|---|---|---|---|
| 24 × 32 | 19.75 × 27.75 | 2.125 | 2.125 |
| 24 × 36 | 19.75 × 27.75 | 2.125 | 4.125 |
Window = artwork − 2 × overlap
Centered border = (outer board − window) ÷ 2
Open this 24 × 32 mat example in the calculator to change the board or overlap. Some suppliers take artwork dimensions and make their own deduction; others want the final window size.
Smaller artwork inside a 20 × 28 outer board
This reverses the question: keep the nominal frame at 20 × 28, then compare smaller pictures. It is useful when a listing says “matted to” a smaller photo size. These are calculated scenarios, not a claim about an included mat.
| Full artwork (in) | Window (in) | Left / right border (in) | Top / bottom border (in) |
|---|---|---|---|
| 12 × 18 | 11.75 × 17.75 | 4.125 | 5.125 |
| 16 × 20 | 15.75 × 19.75 | 2.125 | 4.125 |
Before comparing a frame listing
- Confirm the full sheet and the portion of the image that must remain visible.
- Identify the nominal insert, outer mat board and exact cut window separately.
- Request the actual back opening, rabbet depth and manufacturer tolerances. Width and height alone cannot establish suitability for thick artwork.
- Use the listed outside dimensions for a visual gallery layout; these tables do not provide them.
Questions about 20 × 28 frames
Is 20×28 the same as 50×70 cm?
20×28 inches is 50.8×71.12 cm. A 50×70 cm sheet is smaller in both directions and should be compared using its measured dimensions.
Does 28×20 mean a different ratio?
It expresses the landscape orientation, 7:5, of the same nominal rectangle. Check the product’s orientation specifications separately.
Compare related frame sizes
Return to the frame-size directory · Work backward from a frame you already own · Understand mat terminology