Dimensions come first
An image described as 1080 × 1350 contains 1,080 horizontal pixels and 1,350 vertical pixels. Multiplying the dimensions gives about 1.46 million pixels, but pixel count alone does not reveal compression or sharpness.
- 1080 × 1080 = 1:1 square
- 1080 × 1350 = 4:5 portrait
- 1080 × 1920 = 9:16 vertical
Resolution is not file size
Two JPEG files can have identical dimensions and very different file sizes because compression settings and image detail differ. File size measures stored data; dimensions measure the pixel grid.
Avoid unnecessary enlargement
Upscaling a small social image creates more pixels but cannot recreate detail that was already discarded. For archiving, keep the largest legitimate rendition available and avoid repeated save-and-recompress cycles.
Calculate megapixels yourself
Multiply width by height, then divide by one million. A 1080 × 1350 image contains 1.458 million pixels, commonly described as approximately 1.46 megapixels. A 4032 × 3024 image contains approximately 12.19 megapixels.
Megapixels are useful for comparing pixel counts, but not for judging sharpness in isolation. A blurry 12 MP image is still blurry.
A repeatable inspection workflow
Save an image you are entitled to use, open ContentDown’s Media Inspector, and select the local file. The browser can report its dimensions and file size without uploading it to our servers.
Compare two versions of the same image: record dimensions, format and byte size, then zoom to inspect fine detail. Different file sizes alone do not prove that one file looks better.