Megapixel Calculator
One megapixel is one million pixels. This tool converts pixel dimensions to megapixels, shows the aspect ratio, estimates print size at your chosen DPI, and works backwards from a megapixel target.
From pixel dimensions
From megapixels and ratio
How it works
Megapixels = width × height ÷ 1,000,000. To find pixel dimensions from a megapixel target, the tool keeps the chosen ratio: width = √(megapixels × 1,000,000 × ratio width ÷ ratio height), then rounds to a whole number.
| Common camera sizes | Pixels | Megapixels | Print at 300 DPI |
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When to use this calculator
- Comparing camera or phone specifications on a like-for-like basis.
- Checking whether a photo has enough megapixels for a specific print size.
- Planning how much you can crop and still leave enough pixels for print.
- Converting between a marketing megapixel figure and real pixel dimensions.
Worked examples
- 6000 × 4000 px = 24 MP. It prints at 20 × 13.3 in at 300 DPI and at 40 × 26.7 in at 150 DPI.
- 4000 × 3000 px = 12 MP. It prints at 13.3 × 10 in at 300 DPI, or 26.7 × 20 in at 150 DPI.
- A 16 × 20 in print at 300 DPI needs 4800 × 6000 px = 28.8 MP, more than most phones provide after cropping.
- 24 MP at 3:2 corresponds to about 6000 × 4000 px; at 4:3 it is closer to 5657 × 4243 px.
Megapixels, quality and cropping
More megapixels give you room to crop and print larger, but they are not a measure of image quality. Lens sharpness, sensor size, focus, motion blur and lighting usually matter more. A sharp 12 MP file will beat a noisy, soft 48 MP file in any print. Where megapixels do help is flexibility: cropping a 24 MP file to half its area still leaves about 12 MP.
Why a 48 MP phone may not deliver 48 MP of detail
Many phones combine groups of pixels (pixel binning) to improve low-light performance, producing a 12 MP output by default. The full 48 MP mode usually requires good light and a steady hand, and even then diffraction and lens limitations can reduce real detail. Judge the final pixel dimensions and sharpness, not the headline number.
Common mistakes
- Confusing megapixels (pixels) with megabytes (file size). They measure different things.
- Assuming more megapixels always means better low-light photos.
- Forgetting that cropping reduces the megapixel count available for printing.
- Comparing a 4:3 camera with a 3:2 camera by megapixels alone while ignoring the aspect ratio difference.
Related tools
How big can I print? · Print size calculator · Image print size checker
Frequently asked questions
What size print can I make from a 24-megapixel photo?
A 24 MP photo is usually 6000 × 4000 pixels. At 300 DPI that prints at 20 × 13.3 inches; at 200 DPI it prints at 30 × 20 inches.
Is a higher megapixel count always better?
More megapixels allow bigger crops and larger prints, but image quality also depends on the lens, sensor size and exposure. A sharp 12 MP photo beats a blurry 48 MP photo for printing.