FRAME SIZE LAB
PICTURE FRAME SIZE GUIDE

11 × 17 frame size

An 11×17-inch sheet needs an 11×17 nominal insert comparison, unless a larger mat board is part of the presentation. A3 and 12×18 are nearby sizes, not interchangeable labels.

Calculate a frame for this 11 × 17 print ↗All picture frame sizes

Reviewed 2026-09-11 · Inches first · Original dimensional calculations

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.

11 × 17 inches in cm, mm and both orientations

Nominal sheet dimensions; conversions are calculated, not tolerance allowances.
MeasurementPortrait / listed orderLandscape / reversed order
Inches11 × 1717 × 11
Centimeters27.94 × 43.1843.18 × 27.94
Millimeters279.4 × 431.8431.8 × 279.4
Aspect ratio11:1717:11

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 11 × 17 sheet

Compare a frame described for a 11 × 17-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.

Tabloid and ledger describe opposite orientations

For the 11×17-inch paper rectangle, portrait and landscape swap the width and height. A drawing or document may use either orientation. Measure the full sheet even when a printer leaves a margin around a smaller image. Those margins belong to the sheet for frame sizing; they need not all be visible through a mat.

11×17 versus 12×18

The 12×18 rectangle adds 1 inch to each dimension, but the ratios differ. A 12×18 sheet cannot be treated as an 11×17 insert. An 11×17 sheet centered on a 12×18 board leaves only 0.5 inch beyond the sheet on each edge, before specifying the window and supplier’s practical limits. The larger boards below show roomier mathematical options.

A3 is wider but slightly shorter

A3 is 297×420 mm; 11×17 is 279.4×431.8 mm. One size is wider while the other is taller, so neither is a simple direct replacement for the other at the stated dimensions. Compare exact dimensions when a print shop uses both naming systems.

With a mat around a full 11 × 17 print

These centered examples use ⅛ inch overlap on each artwork edge, producing a 10.75 × 16.75-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.

Borders are measured from the window to the outer board edge; the frame lip can hide part of them.
Outer board / nominal frame (in)Window (in)Left / right border (in)Top / bottom border (in)
16 × 2010.75 × 16.752.6251.625
18 × 2410.75 × 16.753.6253.625
16 in nominal board width10.75 × 16.75MAT OPENING · IN
11 × 17 artwork modeled inside a 16 × 20 outer board. The outline represents the nominal board boundary, not the frame molding.

Window = artwork − 2 × overlap
Centered border = (outer board − window) ÷ 2

Open this 16 × 20 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 11 × 17 outer board

This reverses the question: keep the nominal frame at 11 × 17, 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.

Centered examples on a 11 × 17-inch outer board, with ⅛-inch overlap per artwork edge.
Full artwork (in)Window (in)Left / right border (in)Top / bottom border (in)
8.5 × 118.25 × 10.751.3753.125
8 × 127.75 × 11.751.6252.625

Before comparing a frame listing

Questions about 11 × 17 frames

Will an 11×17 poster work in a 16×20 mat?

A 16×20 board can contain the full nominal sheet. The modeled window gives wider side borders than top/bottom borders, as shown below; check the actual supplied mat.

Can I use two Letter sheets to estimate 11×17?

Two 8.5×11 rectangles side by side along their 8.5-inch edges form a 17×11 rectangle. This illustrates size only and does not specify a multi-opening mat.

Compare related frame sizes

Return to the frame-size directory · Work backward from a frame you already own · Understand mat terminology