Updated September 16, 2026 — by César, editor at AestheticPoster
No IKEA frame exactly matches our M 30×42, L 42×60, and XL 60×84 cm formats (≈ A3, A2, and A1): their range follows round sizes (30×40, 40×50, 50×70, 61×91 cm), not the ISO standard. The best fit is XL in a 61×91 cm frame; M and L require a mat.
Key takeaways
- The 30×40 cm frame, often sold as "A3 size," is 2 cm too short for an M poster at 42 cm tall: it won't fit.
- Compatible frames: 40×50 cm for M, 50×70 cm for L, 61×91 cm for XL.
- Alternative with no measuring or cutting: order a poster already framed (+50 € for M, +70 € for L, +100 € for XL).
Why IKEA sizes never match poster formats
Our posters follow the ISO 216 ratio (1:1.41): M 30×42, L 42×60, XL 60×84 cm. IKEA uses round sizes inherited from film photography — 21×30, 30×40, 40×50, 50×70, 61×91, 70×100 cm — at a ratio close to 4:3 or 5:4. The two grids never align: you must choose the larger frame and manage the margin.
| AestheticPoster Format | Dimensions | Smallest IKEA Frame That Fits | Margin Per Side (Width / Height) |
|---|---|---|---|
| M (≈ A3) | 30 × 42 cm | 40 × 50 cm | 5 cm / 4 cm |
| L (≈ A2) | 42 × 60 cm | 50 × 70 cm | 4 cm / 5 cm |
| XL (≈ A1) | 60 × 84 cm | 61 × 91 cm | 0.5 cm / 3.5 cm |
The 30×40 trap for an M poster
This is the most common mistake. The 30×40 cm frame seems made for an M because the width matches (30 cm on both sides). But its height, 40 cm, is 2 cm shorter than the poster (42 cm): it won't fit, regardless of which way you mount it. True for all ranges sold in this size: RÖDALM, LOMVIKEN, SILVERHÖJDEN, FISKBO, KNOPPÄNG. Check the height, not just the width.
Which IKEA frame for M, L, XL
M poster 30×42 cm → 40×50 cm frame. Margin of 5 cm on the sides, 4 cm top and bottom. Two options: custom mat with 30×42 cm window (cleanest look), or direct mounting centered on a neutral background (white, light oak) — the slight asymmetry stays subtle.
L poster 42×60 cm → 50×70 cm frame. Margin of 4 cm in width, 5 cm in height: same solutions as for M, 42×60 cm window. The 40×50 cm won't work: its width (40 cm) is less than the poster (42 cm).
XL poster 60×84 cm → 61×91 cm frame. The best fit of the three: 5 mm of play per side in width, 3.5 cm in height. It's the largest common size in stores, before the 70×100 cm. An XL designed as a focal point of your wall simply centers on the background, without a mat or with a thin mat for a gallery look.
Mat: when it's essential
Simple rule: beyond 2 cm of margin per side, a mat greatly improves the look. Only XL in a 61×91 cm frame can do without. For M (40×50) and L (50×70), the margin exceeds 4 cm: without a mat, the poster looks floating at the slightest shift. Border width, acid-free cardboard, glass or acrylic: all covered in our guide how to frame a poster. If the poster has a curl when it leaves the tube, flatten it before framing.
The alternative: poster delivered already framed
If you don't want to measure or cut, every AestheticPoster can be ordered framed: black, white, light wood, or dark wood frame, tailored exactly to size, for +50 € for M, +70 € for L, +100 € for XL (69.99 / 99.99 / 149.99 €). Zero margin to manage, 250 g/m² matte paper with no gloss. Without a frame, the adhesive strips included allow hole-free mounting.
FAQ
Is the IKEA 30×40 frame suitable for an M poster (A3)?
No: its height of 40 cm is 2 cm shorter than the poster (42 cm), it won't fit. The smallest IKEA frame that holds an M is the 40×50 cm, with a mat or neutral background.
Can an XL poster (A1) fit in an IKEA 70×100 frame?
Yes, but with 5 cm margin in width and 8 cm in height per side: mat required. The 61×91 cm remains the best choice for XL, with 5 mm of play in width.
IKEA frame or pre-framed poster: how to choose?
Frame already at home or want a wide mat: IKEA, with mat for M and L. Exact fit with no measuring or cutting: pre-framed poster, +50 € for M, +70 € for L, +100 € for XL.
Find the visuals that fit your frame in our decoration posters; to design a complete wall, see the buying guide and our 7 gallery wall plans.
César, editor at AestheticPoster — I measured the IKEA rebates against our three formats before writing this guide, including the 30×40 frame.
