Free tool
Poster Resizer & Aspect Ratio Planner
See how your image fits an A5, A4, A3, A2 or A1 poster: how much would be cropped, where borders would appear, and which orientation suits it best. Everything runs in your browser - your image is never uploaded or stored.
Crop or borders?
Every A-series poster has the same shape, about 1 : 1.414. Most cameras, phones and AI tools produce other shapes, so something has to give: either part of the image is trimmed to fill the poster, or the whole image is kept with plain borders. This tool shows the trade-off for your image; it does not judge sharpness.
FAQ
What aspect ratio is an A3 poster?
All A-series sizes share the same ratio of 1 : 1.414 (the square root of two). A3 is 297 × 420 mm, so portrait is about 0.71:1 and landscape about 1.41:1. An image that fits A3 also fits A5, A4, A2 and A1 without any extra cropping.
Will my photo be cropped when printed?
Only if its shape differs from the A-series ratio and you choose to fill the poster. Most phone photos are 4:3 or 3:2, so a small strip is trimmed from one edge. The tool above shows exactly how much.
How do I make a square image fit an A-series poster?
Either crop about 29% from one side to fill the poster, or keep the whole square and accept plain borders above and below (portrait) or at the sides (landscape). Borders keep every part of the image.
Should I crop or use borders?
Crop to fill when the important subject sits well away from the edges. Use borders when nothing can be lost, such as artwork with text or a signature near the edge. If the crop shown above removes something you care about, choose borders.
Can I resize an AI-generated image for poster printing?
Yes. AI tools often export square or 16:9 images, which need cropping or borders for A-series. Check the shape here, then check sharpness with the AI Artwork Print Checker before ordering.