Buying a 14 x 18 frame online is a gamble until you understand one thing: frames are measured by their inside opening, not the outside edge. A seller’s “14 x 18” listing can mean the glass size, the mat window, or the outer frame dimension, and those three numbers are never the same. This guide walks through measuring your artwork, choosing between a mat and a direct fit, and confirming what a seller’s listed size actually refers to.
What Does 14 x 18 Actually Measure?
The frame is designed to hold a print that measures 14 inches wide and 18 inches high when you frame it directly, with no mat between glass and paper.
If you’re working in metric, 14 x 18 inches equals 35.56 x 45.72 cm.
Here’s the catch: some sellers list the inner opening, some list the glass, and some list the outer frame measurement. Two frames both labeled 14 x 18 can hold different-sized prints. Confirm which dimension the seller means before you order.
How Do You Measure Artwork for a 14 x 18 Frame?
Measure your artwork’s width and height with a rigid tape measure or metal ruler, record both numbers, and compare them against 14 x 18 to decide whether the piece fits directly.
- Lay the artwork flat on a clean, hard surface.
- Measure the width edge to edge — across the widest point, not the average.
- Measure the height the same way.
- Write both numbers down and use that measured size as your frame size when ordering custom framing.
A flexible cloth tape sags and reads long, which is why a metal ruler or rigid tape is the tool here. If your print measures exactly 14 x 18, a stock 14 x 18 frame is the direct fit. If it’s 13 7/8 or 18 1/4, you’re past the standard fit and into trimming or matting territory.
Aspect ratio matters too. A print with the same width but a different proportion will crop if forced into a 14 x 18 opening, so check that your artwork’s width-to-height ratio matches the frame’s before assuming it fits.
Does a Mat Change the Frame Size You Need?
A mat changes the relationship between your artwork and the frame. The mat opening is cut smaller than the artwork so the mat overlaps the paper’s edges and holds the print in place — meaning a matted 14 x 18 frame holds a print smaller than 14 x 18.
Either way, the artwork sits behind the mat, not flush with the frame opening.
The frame itself must then be sized to the mat’s outer dimensions, not the artwork’s. If you want a 2-inch mat border around a small print, that mat’s outer size — not the print’s — determines which frame you buy.
Two options, framed plainly:
- No mat: buy a 14 x 18 frame for a 14 x 18 print. Simple, exact, nothing trimmed.
- With a mat: buy a 14 x 18 frame whose mat opening matches your print, and confirm the mat’s outer size equals the frame opening.
Which Frame Size Should You Order?
Match the frame’s opening to the largest element it holds: the artwork when framing without a mat, the mat’s outer edge when framing with one.
| Your Situation | Frame Opening Needed | Notes |
|---|---|---|
| Print measures exactly 14 x 18, no mat | 14 x 18 | Direct fit, nothing trimmed |
| Print is 14 x 18 with a 2-inch mat border | 14 x 18 (mat outer = opening) | Print sits behind the mat |
| Print is smaller than 14 x 18, with mat | 14 x 18 frame, custom mat opening | Cut mat 1/8 in. smaller than print |
| Print has a different aspect ratio | Not a direct fit | Trim the image or add a mat |
| Seller lists “glass size” instead | Verify before ordering | Opening and glass can differ |
| Ordering custom framing | Your measured width x height | Use the measured artwork size |
| Metric sizing needed | 35.56 x 45.72 cm | Equivalent to 14 x 18 inches |
IKEA’s own framing guidance and Frame USA’s size reference both stress checking the inside dimension rather than trusting the label alone. If you’ve measured and you’re ready to buy, this roundup of the best 14 x 18 picture frame options covers tested picks that match the standard opening. For the official sizing reference, Frame Destination’s standard picture frame size guide lists 14 x 18 among the stocked US sizes.
Before you add anything to a cart, confirm three numbers: your artwork’s measured width and height, the mat opening if you’re using one, and whether the seller’s listed size refers to the inside opening, the glass, or the outer frame. When all three line up at 14 x 18, you have a direct fit. When they don’t, you either trim the print, order a custom mat, or size up the frame — and knowing which one before you order saves the return shipping.
FAQs
Is a 14 x 18 frame the same as 14 x 18 inches of glass?
Not always. Some sellers list the inside opening, some list the glass size, and some list the outer frame measurement. Glass and opening usually match on a well-made frame, but the outer frame is always larger after the molding width is added. Verify which dimension the listing means before ordering.
Can I put a smaller print in a 14 x 18 frame?
Yes, with a mat. The mat’s outer edge must match the frame opening at 14 x 18, while the mat window is cut smaller to hold your print.
What if my artwork is 14 x 18 but a different shape?
Then it won’t fit without adjustment. The frame opening matches the print’s proportions, so a print with the same width but a taller or shorter height will crop against the edges. Trim the image to match the ratio, or use a mat to absorb the difference between the print and the opening.
References & Sources
- Frame Destination. “Picture Frame Sizes Guide” Lists 14 x 18 among standard US frame sizes and covers inside-opening measurement.
- Frame USA. “Picture Frame Sizes” Reference for standard frame dimensions and ordering by measured artwork size.
- IKEA. “Finding the Right Picture Frame” Guidance on matching frame openings and mat openings to artwork.
