How to Crop an Image to a Ratio: 1:1, 4:5, 9:16, 16:9 and More

An aspect ratio describes only the shape of a picture: width divided by height, written as two small whole numbers. A 1920 × 1080 px frame and a 1280 × 720 px frame are both 16:9, because dividing each side by the largest number that fits into both (120 and 80) gives 16 and 9. The pixel size, on the other hand, describes how much detail the frame holds. Two images can share a ratio and differ fourfold in pixels, and two images with almost the same pixel count, such as 1080 × 1350 and 1200 × 1200, can have different shapes.

This matters because platforms check the two things separately. Instagram, a print lab or a slide template first looks at the shape and crops, letterboxes or rejects anything that does not match. Only then does it scale the pixels to its display size. If you get the shape right yourself, the platform has nothing left to decide, and the framing you chose is the framing people see. If you only get the pixel count right, the platform still crops whatever shape you sent.

The sensor you shoot with sets the starting ratio. Most phone cameras record 4:3 (an iPhone 12 MP photo is 4032 × 3024 px), while most interchangeable-lens cameras record 3:2, the shape of 35 mm film. Every crop to a different ratio throws away part of that frame, and the further the target shape is from the original, the more you lose.

Most requirements fall into a handful of shapes. Square 1:1 is the default for profile pictures, marketplace listings and avatars, because the site can then show it as a square or cut a circle from it without surprises. The Instagram feed accepts anything from 1.91:1 landscape to 4:5 portrait, and 4:5 at 1080 × 1350 px takes the most screen height. Stories, Reels, TikTok and YouTube Shorts are full-screen 9:16. YouTube recommends 1280 × 720 px for custom thumbnails, under 2 MB, and PowerPoint has used 16:9 as the default slide size since PowerPoint 2013. For per-platform pixel sizes, see the Instagram post and story sizes guide.

Prints and documents use their own set. A 4 × 6 in print is 2:3 (or 3:2 turned sideways), 8 × 10 in is 4:5 and 5 × 7 in is 5:7, so the same photo needs a different crop for each size of frame. Passport photos are defined in millimeters: 35 × 45 mm in the UK, the EU, India and many other countries, which works out to 7:9, while the US passport photo is a 2 × 2 in square. The passport photo maker crops to these sizes and also checks head height, which a plain ratio crop does not.

Three operations change how an image fits a frame, and they are easy to confuse. Cropping cuts pixels away at the edges and leaves the rest untouched, so it changes the shape and lowers the pixel count. Resizing scales every pixel up or down and keeps the whole picture, so it changes the pixel count and keeps the shape. Padding, also called letterboxing (bars above and below) or pillarboxing (bars at the sides), adds a plain border so the picture fits a new shape without losing anything.

A typical job uses two of them in a row. To turn a 4032 × 3024 px phone photo into a 1080 × 1350 px Instagram post, you crop it to 4:5 (about 2419 × 3024 px) and then resize it down. To fit a wide group photo into a square without cutting anyone off, you pad it to 1:1 instead. The image resizer does either in one pass: set both sides and choose Crop to fill or Pad with color under Fit.

A ratio lock fixes the shape of the box, not where it sits, and that placement is what makes a crop look deliberate. The rule of thirds is the usual starting point: imagine the frame split by two horizontal and two vertical lines and put the subject, or the eyes in a portrait, on one of those lines rather than dead center. Most crop screens draw that grid while you drag. For a square profile picture, centering works better, because the site may cut a circle from it and anything near the corners disappears.

Headroom is the space above a head. Too much makes a person look small and sunk in the frame; none at all, with the top of the head touching the edge, looks cramped. In a 9:16 crop from a landscape photo, give the subject a little room in the direction they face or move, called lead room, so the picture does not feel blocked in.

Platforms also cover parts of the frame with their own interface. Stories and Reels put the profile name at the top and the reply bar and captions at the bottom, so keep text out of roughly the top and bottom 250 px of a 1080 × 1920 frame. YouTube prints the video length in the bottom-right corner of every thumbnail. Put titles and faces where nothing will sit on them.

Every major photo app can lock the crop box to a ratio, though none of them lets you type an exact pixel size. On an iPhone, the Photos app keeps the original, so you can return to it later with Revert. Google Photos on Android offers Save as copy next to Save if you want to keep both versions. The steps below are for the current versions of each app; menu names have moved around between releases, but the ratio button has stayed in the crop screen.

On Windows 11, open the picture in Photos, press Edit image (Ctrl + E) and pick the crop tab. The Aspect ratio menu offers Free, Original, Square and fixed shapes such as 16:9, 4:3 and 3:2; drag the box, then choose Save as copy so the original stays intact.

On a Mac, Preview is the opposite: it has no ratio menu, but it shows the selection size in pixels while you drag. Holding Shift locks the box to a square, which covers 1:1. For any other ratio you watch the numbers until they match, or calculate them first: for 4:5 on a 3024 px tall photo, the width is 3024 × 4 ÷ 5 = 2419 px.

When a form asks for a precise size, such as 1200 × 628 px for a link preview or 600 × 600 px for a visa photo, a ratio lock gets you the shape but still leaves a resize to do. A crop box set in pixels does both at once. The crop tool offers nine fixed ratios under Aspect ratio, plus Free for freehand and Custom size (px) for an exact Width and Height. It runs in any browser, on a phone too, with nothing to install and no sign-up.

The same box can be applied to up to 20 images at once, each up to 95 MB. That is useful for product photos shot on the same table, screenshots of the same window, or a set of headshots for a team page. Start position decides where the box lands on every file: center, an edge, a corner, or Smart (subject), which looks for the main face or object in each photo separately. Files are deleted from the server 30 minutes after processing.

A circle crop is a square crop with the corners removed, so it always starts from 1:1. What happens to those corners depends on the file format. PNG, WebP and AVIF store transparency, so the corners become see-through and the circle sits cleanly on any background. JPG has no transparency at all; the corners must be filled with a color, usually white. If you upload a JPG circle to a site with a dark theme, the white corners show up as a square around the round picture.

In the crop tool, set Shape to Circle and choose PNG or WebP as Output format; Outside the circle then stays on Transparent. For a JPG, pick white, black or a Background color that matches the page where the picture will appear. Most chat apps and social networks cut their own circle from a square upload anyway, so for those a plain 1:1 crop with the face centered is enough. A pre-cut circle is worth it for email signatures, slides and documents.

Cropping does not blur or soften the pixels you keep; it only removes the others. The quality question is about saving the result. A PNG is lossless, so a cropped PNG is pixel-for-pixel identical to that area of the original. A JPG has to be decoded and encoded again, which adds one more round of compression. At the default Quality of 85 that single re-save is not visible, but cropping the same JPG five times in a row, saving each time, stacks five rounds of loss. Keep the original and crop from it every time.

The crop also has fewer pixels, which is where perceived quality goes. A 9:16 crop from a 4032 × 3024 px landscape photo keeps only about 1701 × 3024 px, roughly 42% of the frame, and that is still plenty for a 1080 × 1920 story. A tight crop of a face from a group shot may leave 400 px or less, which looks soft on any modern screen. File size usually drops along with the pixel count, so a crop is also the first step when a photo must fit under a KB limit.