Plan an upscale before you render it. Type the size of your image; the results update as you type. Everything runs in your browser and nothing you enter is sent or stored.
How the numbers are calculated
| Result | Formula | Example (1920 x 1080) |
|---|---|---|
| Megapixels | width × height ÷ 1,000,000 | 2,073,600 pixels = 2.07 MP |
| Aspect ratio | width and height divided by their greatest common divisor | 16:9, or 1.778:1 |
| Print size | pixels ÷ PPI = inches; inches × 2.54 = cm | 6.4 x 3.6 in at 300 PPI |
| Output size at scale s | width × s, height × s | 3840 x 2160 at 2x |
| Predicted share | 1 − 1/s² | 75% at 2x |
| Largest crop at a ratio | keep the full height and trim the width, or the reverse, whichever fits | 864 x 1080 for 4:5 |
| Largest scale under a cap | √(cap × 1,000,000 ÷ (width × height)), rounded down | 3.49x under 25.3 MP |
The print formula is the one Mpix publishes: pixels ÷ DPI = size in inches (Mpix help). Shopify uses the same megapixel formula, (width × height) ÷ 1,000,000, in its image help. When the reduced ratio has large numbers (1366 x 768 is 683:384), the calculator also names the common ratio within 1%.
Size limits worth planning around
| Limit | Value | Source |
|---|---|---|
| Magnific Creative upscaler, API output | 25.3 million pixels | Magnific API docs |
| Topaz Gigapixel, largest output | 32,000 pixels on the longest side (about 1 gigapixel) | Topaz Gigapixel docs |
| Topaz Gigapixel, "very large" upscale | 256 MP or more, which needs at least 128 GB of RAM on Apple silicon Macs | Topaz system requirements |
| Adobe Super Resolution | Exactly 2x width and height, 4x the pixels | Adobe |
| Upscayl | AI at 4x; above 4x only resizes, except 16x Double Upscayl | Upscayl interface text |
| Shopify theme image upload | 20 megapixels and 20 MB | Shopify help |
All limits checked 13 November 2026.
How to use the results
- Pick the scale your tool renders. Most models work at fixed scales (2x or 4x), so choose the row that reaches your target and resize down from there.
- Watch the predicted share. Above 4x, more than 93.75% of the output is new. Check text and faces at 100% before you deliver.
- Crop before you upscale. Cropping first means the upscaler spends its time only on the pixels you keep.
To understand what those predicted pixels are, read how AI upscaling works. To decide whether an upscale is worth it at all, read when upscaling actually helps.