Photography Calculators

Studio, storage & utilities

Aspect Ratio Crop Calculator

Going 3:2 to 16:9 (or to 8×10) is a crop, not a squeeze. This fits the target aspect inside the source and reports the pixel rectangle, how many pixels remain, and the percent lost. Compose with the crop in mind — a test shot in the camera’s 16:9 mask beats discovering a missing head in the edit.

Inputs

Units
px

Pixel width of the file or sensor readout.

px

Pixel height. 6000×4000 is a typical 3:2 24 MP file.

16 for 16:9, 4 for 4:5 / 8×10, 1 for square.

9 for 16:9, 5 for 4:5 / 8×10, 1 for square.

Results

Cropped width
6,000px

Width of the centred crop, rounded to whole pixels.

Cropped height
3,375px

Height of the centred crop, rounded to whole pixels.

Pixels kept
20,250,000

Cropped width × cropped height.

Pixels discarded
15.6%

Share of the source pixels outside the crop.

The Result is indicative and educational. It does not constitute a design, a technical opinion or medical advice and does not replace calculations or verification by a person with the appropriate qualifications and authorisations. Before purchase, installation or use in practice – in particular in electrical installations – the Result should be verified by a qualified specialist. Details: Terms of Service, point 4.

Example products

Product links are Affiliate Links to Amazon websites. Using them does not cost you anything extra, and if you make a purchase we may receive a commission. Details: Terms of Service, point 5.

Calculation method

Compare source aspect (width/height) to the target (tw/th). If the source is relatively wider, keep full height and set crop width to height times tw/th. If the source is taller, keep full width and set crop height to width times th/tw. If that rectangle would exceed the source, it is clamped. Each side is rounded to whole pixels, so pixels kept are exactly crop width times height; percent lost is the rest of the original pixel count.

Exact formula

If source is wider than target, cropHeight = height, cropWidth = height × tw/th. Else cropWidth = width, cropHeight = width × th/tw. Clamp to source and round each side to whole pixels. percentLost = 100×(1 − cropPixels/sourcePixels). Limits: Content-aware crop, rotation and anamorphic pixel aspect omitted.

In-camera aspect vs post

In-camera 16:9 on some bodies is a true readout crop (you cannot recover). On others it is a JPEG mask on a 3:2 RAW. Know which you own.

Social crops

From a horizontal 3:2 frame, a vertical 4:5 keeps about 53% of the pixels and 9:16 only 37.5%, against 84% for 16:9. Turn the camera, or shoot a little wider than feels right, if the post is vertical.

Frequently asked questions

3:2 to 16:9, how bad is it?

A 6000×4000 file becomes 6000×3375. You lose the top and bottom — about 15.6% of the pixels. That is a lot of sky or feet. Frame loose.

Print 8×10 from 3:2?

8×10 is 4:5. A 6000×4000 frame keeps 5000×4000 when the print has the same orientation as the frame (16.7% gone), but only 3200×4000 if you cut a vertical print from a horizontal frame (46.7% gone). Do not compose a couple against both edges of a 3:2 viewfinder if the order is 8×10.

Anamorphic?

Desqueeze first (pixel aspect), then crop. This tool assumes square pixels.

More in this topic

All tools in this topic