Understanding aspect ratios is fundamental to working with images. The aspect ratio is the proportional relationship between width and height, expressed as two numbers separated by a colon (e.g., 16:9, 4:3, 1:1).
Common aspect ratios and their uses include 1:1 (square, Instagram posts), 4:3 (classic photos, presentations), 3:2 (DSLR photos, standard prints), 16:9 (widescreen, YouTube), 9:16 (Stories, TikTok), 4:5 (Instagram portrait), and 2:3 (Pinterest).
To calculate the aspect ratio of an image, divide both width and height by their greatest common divisor. For example, 1920x1080 simplifies to 16:9 (divide both by 120).
To find new dimensions while maintaining a ratio, decide your target width and multiply by the ratio. For a 16:9 image at 1200px wide: height = 1200 * 9/16 = 675px.
With ImgTools, the Crop tab provides preset ratios for all common formats. Select your ratio, crop, then resize to your target dimensions.
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