Crop Zoom Resolution Calculator
Fill in the values and the answer updates as you type.
How the Crop Zoom Resolution Calculator works
Cropping by a factor z divides both width and height by z, so the pixel count falls by z². The field of view matches a lens z times longer. This is a free way to reach farther when you cannot change lenses, but high-ISO noise and softness become more visible. Keep the crop above the resolution your print or screen needs. Example: A 2× crop of a 6000 × 4000 px photo leaves 3000 × 2000 px, or 6 MP, and frames like a 100 mm lens.
Inputs and results
The Crop Zoom Resolution Calculator takes 4 inputs and gives 4 results.
What you enter
- Original width (px) — starts at 6000.
- Original height (px) — starts at 4000.
- Crop zoom factor (×) — starts at 2.
- Lens focal length (mm) — starts at 50.
What you get
- Resolution after crop
- Megapixels left
- Equivalent focal length (mm)
- Pixels discarded
Example: Crop Zoom Resolution Calculator with the starting values
With original width 6000 px, original height 4000 px, crop zoom factor 2 × and lens focal length 50 mm, the calculator returns:
| Resolution after crop | 3000 × 2000 px |
|---|---|
| Megapixels left | 6 |
| Equivalent focal length (mm) | 100 |
| Pixels discarded | 75% |
Change any value above and the results update straight away.
Crop Zoom Resolution Calculator FAQ
How do I use the Crop Zoom Resolution Calculator?
Enter original width, original height, crop zoom factor and lens focal length in the fields, then read resolution after crop, megapixels left, equivalent focal length (mm) and pixels discarded in the result panel. The answer updates as you type, and you can press Calculate or Enter to refresh it. Use “Copy link” to share your exact numbers with someone else.
What does the Crop Zoom Resolution Calculator calculate?
Resolution left after cropping in to simulate a longer lens. It returns resolution after crop, megapixels left, equivalent focal length (mm) and pixels discarded from the 4 values you provide.
What values does the Crop Zoom Resolution Calculator start with?
It opens with original width 6000 px, original height 4000 px, crop zoom factor 2 × and lens focal length 50 mm so you can see a working result straight away. Replace them with your own numbers, or press Reset to return to these starting values.
Is the Crop Zoom Resolution Calculator free and private?
Yes. It is free, needs no account, and runs in your browser, so nothing you type is sent to or stored on our servers. See the Privacy Policy for details.
Can I rely on the Crop Zoom Resolution Calculator for important decisions?
Treat the result as a well-rounded estimate. Real situations often have details a general calculator cannot know, so confirm important decisions with a qualified professional. See the Disclaimer for more.