Image file size calculator
Free · no sign-upEstimate an image's file size from its dimensions and colour depth.
Compressed formats (JPG, PNG, WebP) are much smaller — the JPEG figure is a rough guide only.
Work out how big an image file will be from its dimensions and colour depth. The raw (uncompressed) size is simply pixels × colour depth — this calculator does it for you, plus a rough JPEG estimate. Free, no sign-up.
- ✓Uncompressed (raw) file size
- ✓Any width, height and colour depth
- ✓Megapixels and a JPEG estimate
- ✓Instant — updates as you type
- ✓Free — no sign-up
Who it's for
- Estimating storage and bandwidth
- Checking upload limits before exporting
- Comparing formats and resolutions
- Learning how image size works
How it works
- 1Enter the width and height.
- 2Pick the colour depth.
- 3Read the raw size and megapixels.
- 4Use the JPEG estimate as a guide.
Frequently asked questions
How do you calculate an image's file size?+
Raw size = width × height × colour depth (in bytes). A 1920×1080 image at 24-bit is 1920 × 1080 × 3 ≈ 5.9 MB uncompressed.
Why is my real JPG so much smaller?+
JPG, PNG and WebP compress the image, often 5–20× smaller than the raw size. The exact figure depends on the content and quality setting.
What colour depth should I pick?+
24-bit (RGB) for most photos, 32-bit (RGBA) when there's transparency, 8-bit for grayscale or indexed images.
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