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Megapixel calculator

Compute the megapixels of an image from its width and height in pixels.

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Enter Width (px), Height (px) and the Megapixel calculator works out Megapixels straight away. For instance, with Width (px) = 4,000 and Height (px) = 3,000 it returns Megapixels = 12.

How to use it

  1. Enter your values: Width (px), Height (px).
  2. Read the result instantly: Megapixels.

Frequently asked questions

What does the Megapixel calculator actually compute?

It takes Width (px) and Height (px) and derives Megapixels from them. The calculation is live as you type, so the result updates on every change.

What information do I need to provide?

2 values: Width (px) and Height (px). Nothing else is required — no account, no file upload.

Can you show a worked example?

With Width (px) = 4,000 and Height (px) = 3,000, the calculator returns Megapixels = 12. Those figures come from running this exact tool, so you can reproduce them by entering the same values.

What happens if I enter larger values?

It moves a lot. Using Width (px) = 8,000 and Height (px) = 6,000 instead, Megapixels goes from 12 to 48 — which is why it is worth testing a few scenarios rather than trusting a single figure.

What does it give for smaller values?

Scaled down to Width (px) = 2,000 and Height (px) = 1,500, Megapixels comes out at 3. The relationship is worth checking at both ends before you rely on a single result.

When would I actually use this?

Finding out how big a thing will be before you make it: how many gigabytes an hour of footage takes, how long a file needs on the connection you have, how large a photo prints before it goes soft, what bitrate fits the budget you were given.

What is the most common mistake?

Taking the advertised connection speed as the transfer speed. A 100 Mb/s line is megabits, the file is in megabytes, and the eight-fold difference between them is where most download estimates go wrong — before overhead and contention take their own share.

What is the difference between the Megapixel calculator and the Aspect ratio calculator?

This one returns Megapixels; the Aspect ratio calculator returns Aspect ratio and Ratio (decimal). That is the whole difference — open the one whose figure you need.

Is there a tool for the next step?

Print size calculator is the closest one after this: Find the maximum print size of an image from its pixel dimensions and DPI.

Where do the figures come from, and how current are they?

Byte prefixes follow the IEC convention where a kibibyte is 1 024 bytes and a kilobyte is 1 000 — drive makers use the second, operating systems often report the first, and a disk that shrinks on arrival is that gap and nothing else. Print sizing assumes 300 dpi unless you change it.

Further reading

All guides →
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