How many megapixels do I lose when cropping?

Cropping reduces megapixels proportionally to the area removed. Cropping to half the width and height keeps only 25% of the pixels (one quarter of the area). A 24MP image cropped in half becomes 6MP. High-resolution cameras (45MP+) give more headroom for cropping.

Is cropping the same as using a longer lens?

Cropping gives the same framing as a longer lens, but with lower resolution and no perspective change. A 50mm crop to 2x gives the framing of 100mm but at quarter the megapixels. It also does not change background compression — only physical distance changes perspective.

How much can I crop and still print?

For a good A4 print at 240 DPI, you need about 8 megapixels (3508x2480px). So a 24MP image can be cropped to about 33% of its area and still produce a quality A4 print. Higher resolution cameras allow more aggressive cropping.

Does crop factor from cropping stack with sensor crop factor?

Effectively yes. If you use a 1.5x APS-C sensor and then crop to half the frame, your effective crop factor is 1.5 x 2 = 3x. A 50mm lens would have an effective FOV of 150mm on full frame.

PhotoCalcs

Crop Calculator — Effective Megapixels After Crop

Calculate the effective megapixels remaining after cropping and the equivalent focal length increase.

Original Width

Original Height

Crop Width

Crop Height

How We Calculate This

Effective Megapixels

Cropped MP = (crop width x crop height) / 1,000,000

Equivalent Crop Factor

Crop factor = original width / crop width

Equivalent FL = 50mm x crop factor

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Last updated: February 2026

All calculations are estimates based on standard optical and photographic formulas. Results may vary with specific equipment.