Image Resolution Calculator
Calculate megapixels, aspect ratio, and print size from pixel dimensions. You can also find the required pixel resolution for a target print size.
1) Calculate from pixel dimensions
2) Calculate required resolution for print
What is image resolution?
Image resolution describes how much detail is in an image. In digital files, that detail is measured in pixels (for example, 1920 × 1080). More pixels generally mean more detail, more flexibility for cropping, and better print quality at larger sizes.
When people search for an image resolution calculator, they usually want to answer one of three practical questions: “How many megapixels is this?”, “What can I print this at?”, or “How large should I export for web or social media?” This page helps with all three.
Pixels, megapixels, and DPI/PPI (quick explanation)
Pixel dimensions
Pixel dimensions are the raw width and height of your image file. A photo that is 4000 × 3000 has 12,000,000 total pixels.
Megapixels (MP)
Megapixels are simply total pixels divided by one million. So 12,000,000 pixels = 12 MP.
DPI/PPI
For screens, PPI/DPI does not change image detail by itself; pixel dimensions do. For print, PPI (or DPI in common usage) determines how densely pixels are packed on paper. Higher density means finer detail.
How to use this calculator
- Enter your image width and height in pixels.
- Enter a print density (commonly 300 PPI for high-quality print).
- Click Calculate from Pixels to get megapixels, aspect ratio, print size, and estimated uncompressed file size.
- Use the second section if you already know your print dimensions and need the required pixel resolution.
Common resolution targets
For websites and blogs
- Header/hero images: 1600–2400 px wide
- Blog content images: 1200–1600 px wide
- Thumbnails: 300–600 px wide
For social media
- Instagram feed: 1080 px wide (square or portrait variations)
- Facebook shared image: around 1200 × 630 px
- LinkedIn post image: around 1200 × 627 px
For printing
- 4 × 6 in at 300 PPI → 1200 × 1800 px
- 8 × 10 in at 300 PPI → 2400 × 3000 px
- 16 × 20 in at 300 PPI → 4800 × 6000 px
Choosing the right resolution for your project
Use the highest resolution your workflow can handle, then export down for delivery. Oversized images can slow page speed on websites, while undersized images can look soft in print.
A practical strategy is:
- Edit from the original high-resolution source.
- Keep an archival master file.
- Export separate versions for web, social, and print.
Frequently asked questions
Is 72 DPI still required for web images?
Not really. Modern screens care mostly about pixel dimensions. The DPI metadata has little impact on web display quality.
Does increasing DPI increase quality?
Only if enough pixels already exist. Changing DPI metadata alone does not add detail. To truly increase detail, you need more pixels from capture or quality upscaling.
What aspect ratio should I use?
That depends on output. Common ratios are 16:9 (video/screens), 4:3 (many cameras/tablets), 3:2 (DSLR/mirrorless), and 1:1 (square social posts). Maintaining aspect ratio prevents distortion.
Final tip
If you are unsure, calculate backward from the final destination: choose your print size or platform requirement first, then generate the needed pixel dimensions. That workflow prevents blurry outputs, unnecessary file bloat, and rework at export time.