Megapixels & Resolution Calculator
Convert dimensions to megapixels, or turn a megapixel count and aspect ratio back into pixel dimensions.
What a megapixel really measures
A megapixel is one million pixels of total resolution — the raw amount of image data a frame contains. It tells you how far you can enlarge or crop before individual pixels start to show, which is why it drives decisions about printing and reframing more than it drives everyday sharpness.
To see what a resolution means on paper, pair this with the DPI & Print Size calculator; to plan the storage those pixels take up, use the Image File Size Estimator.
Frequently Asked Questions
How are megapixels calculated?
Multiply the width by the height in pixels, then divide by one million. A 6000×4000 image is 24,000,000 pixels, which is 24 megapixels. 'Mega' simply means million, so a megapixel is one million pixels — the total count, not either dimension on its own.
Why does my camera's stated megapixels differ slightly from width × height?
Manufacturers quote 'effective' megapixels, and sensor dimensions are often rounded in the spec sheet. A sensor described as 24 MP might actually record 6000×4000 (24.0 MP) or 6016×4000 (24.06 MP). Small differences between the badge number and width × height are normal.
How do I find the dimensions for a given megapixel count?
You also need an aspect ratio, because many different width/height pairs share the same total. Given megapixels and a ratio, the tool solves height = √(total pixels × ratioH ÷ ratioW) and width = height × ratioW ÷ ratioH. For example 12 MP at 4:3 works out to 4000×3000.
Do more megapixels mean better photos?
Not by themselves. Megapixels set how large you can print or how much you can crop before pixels become visible, but image quality also depends on the lens, sensor size, dynamic range, and light. Beyond what your output actually needs, extra megapixels mainly add file size.
Educational estimate only. Solved dimensions are rounded to whole pixels, so the actual megapixels can differ slightly from the target.