Why we lay sizes out instead of cropping them
A square master cropped to a banner keeps 12% of its height. What a layout keeps instead.
In shortCropping keeps one window of the master and loses the rest; a layout places the same parts again in the room each shape has. We measured what a crop keeps across a typical set: a square master cropped to a 728×90 banner keeps 12% of its height, and a 9:16 cut from a 4:5 master keeps 70% of its width. The parts at the edges, usually the logo, the price and the legal line, are what a crop loses first.
On this page
When we started laying out sizes for real sets, the first question everyone asked was why not crop. Cropping is fast, every tool does it, and for some sizes it looks fine. So we measured what a crop keeps of a master for each shape in a typical media plan, and where the parts that matter sit.
What a crop keeps
A crop from one shape to another keeps the share of the master that the new shape’s proportions allow, and no more. Worked out for the shapes a typical plan asks for:
| From the master | To | A crop keeps |
|---|---|---|
| Square, 1:1 | 728×90 leaderboard1 | 12% of the height |
| Square, 1:1 | 300×2501 | 83% of the height |
| Portrait, 4:5 | Story, 9:1623 | 70% of the width |
| Square, 1:1 | Story, 9:162 | 56% of the width |
Worked out from each pair of shapes: the share of the master’s height or width the new shape keeps at full width or height.
What a crop loses
The share kept is only half the problem. The other half is where the parts sit. In most masters, the photo fills the middle and the words sit at the edges: the logo and headline at the top, the price and button at the bottom, the legal line at the very foot. A crop that keeps the middle keeps the photo and loses exactly those parts. A crop that keeps the top keeps the logo and loses the price.
The legal line is lost most often, because it sits at the outer edge and is the smallest part. That matters more than its size suggests: the FTC’s guidance asks for a needed disclosure to work on every device the ad runs on, including space-constrained ads.4
What a layout does instead
A layout takes the master’s parts (photo, logo, headline, price, button, legal line) and places them again in the room the new shape has. On a 728×90 banner that means a row: the photo at one end, the headline beside it, the price and the button at the other end, the legal line under them. On a Story it means a stack, kept inside the bands Meta asks to stay clear: 14% at the top, 35% at the bottom and 6% at each side.2
A layout also has to keep the words readable at the size it gives them. On the smallest sizes that is the real constraint: small text needs a contrast of at least 4.5:1 against what is behind it,5 which often means a flat panel under the words rather than the photo.
What it means for your sets
- Crop only when the new shape is close to the master’s and nothing important sits at the edge you lose.
- Lay out every shape that changes proportion a lot: the banners and the tall sizes always.
- Check the legal line on every size first. It is the part a crop loses first.
This is why eonik’s Resize lays each size out around the master’s parts rather than cropping, and shows every size beside the others before it makes them.
How to resize one ad into every placement →Sources
- About common sizes for responsive display ads, Google Ads Help. Common display sizes on computers and mobile.Checked 25 Oct 2026
- Image ad specs on Instagram Stories, Meta Ads Guide. 9:16, 1440×2560, and the 14% / 35% / 6% safe zone.Checked 25 Oct 2026
- Image ad specs, Facebook Feed, Meta Ads Guide. 4:5, 1440×1800.Checked 25 Oct 2026
- .com Disclosures: How to Make Effective Disclosures in Digital Advertising, US Federal Trade Commission, March 2013. Disclosures close to the claim, on every device the ad runs on, including space-constrained ads.Checked 26 Oct 2026
- Success Criterion 1.4.3, Contrast (Minimum), W3C, Web Content Accessibility Guidelines 2.2. 4.5:1 for text, 3:1 for large text, and logos exempt.Checked 26 Oct 2026