Need to keep 16:9 but only know the width? Or scaling a 1920×1080 photo to 800 pixels wide? Type what you know — we'll fill in the rest. No upload needed.
Type the values you know — width, height, ratio numerator, or ratio denominator. Leave one blank.
Updates as you type. Lock a ratio with the 🔒 button to keep it fixed while you change width or height.
Click any value to copy. Common presets (16:9, 4:3, 1:1, 9:16, 4:5) are one tap away.
Single photos: this tool. Whole camera roll? SwipePhotos works directly on your Apple Photos library — no exporting and re-importing. Swipe through years of bursts and duplicates in a weekend. 100% on-device.
16:9 — the standard HD widescreen ratio. 4K (3840×2160) is also 16:9.
Instagram portrait posts. Best ratio for in-feed photos because it takes up the most vertical space without getting cropped.
If you know the original ratio (e.g., 16:9 = 1.778), set the new width and multiply by 1/1.778 to get the height. This calculator does that for you — just type the new width and read off the height.
Resolution is the actual pixel dimensions (e.g., 1920×1080). Aspect ratio is the proportions, irrespective of size (16:9). 1920×1080 and 3840×2160 are both 16:9, but the second has 4× the pixels.