Image Resolution Calculator

1. Enter the width of the image in pixels.
2. Enter the height of the image in pixels.
3. Read the resolution in megapixels.
4. See the total pixels and the aspect ratio.

Here is what each result means:

Image resolution is the number of pixels an image contains, usually given as width by height, like 4000 by 3000. Each pixel is one tiny dot of color, and more pixels capture finer detail.

Resolution is often summarized as megapixels, meaning millions of pixels. A 12 megapixel image holds about 12 million pixels in total. The megapixel figure is a quick way to compare how much detail different cameras or images can hold.

Megapixels are just the total pixel count expressed in millions. Multiply the width by the height, then divide by one million.

1. Multiply the width in pixels by the height in pixels.
2. That gives the total pixel count.
3. Divide by one million to get megapixels.

The aspect ratio comes from reducing the width and height by their greatest common divisor, the same shape whatever the resolution.

Take a photo that is 4000 pixels wide and 3000 pixels tall.

Calculation: multiplying 4000 by 3000 gives 12,000,000 pixels. Dividing by one million gives 12 megapixels. Reducing 4000 and 3000 by their common divisor of 1000 gives a 4:3 aspect ratio. So this is a 12 megapixel image in the classic 4:3 photo shape.

Here are resolutions you will meet often, with their megapixel counts.

Not by themselves. Megapixels measure how much detail an image can hold, which matters for cropping and large prints. But image quality also depends on the sensor, the lens, lighting, and processing.

A 12 megapixel photo from a good camera can look better than a 48 megapixel one from a small, noisy sensor. Treat megapixels as one factor among several, not a single score for quality.

Comparing Cameras or Images

Check how many megapixels a given resolution works out to, so you can compare devices on the same scale.

Planning Crops

See how many pixels you start with, so you know how much you can crop and still keep enough detail.

Checking Upload Requirements

Confirm an image meets a minimum resolution or megapixel requirement before submitting it.

1. Confusing Megapixels With Aspect Ratio

Megapixels count total pixels; aspect ratio is the shape. Two images can share 12 megapixels yet have different shapes and dimensions.

2. Assuming More Megapixels Always Looks Better

Sensor size, lens, and lighting matter as much as pixel count. A high megapixel number does not guarantee a sharper photo.

3. Mixing Up Resolution and File Size

Resolution is the pixel count. File size also depends on compression and format, so two 12 megapixel images can have very different file sizes.

4. Forgetting That Cropping Reduces Resolution

Every crop throws away pixels, lowering the megapixel count. Start with more resolution if you plan to crop heavily.

The math is exact arithmetic. Megapixels are rounded for display, and the aspect ratio uses whole-pixel dimensions.

Multiply the width in pixels by the height in pixels, then divide by one million. A 4000 by 3000 pixel image is 12,000,000 pixels, which is 12 megapixels.

Image resolution is the number of pixels in an image, given as width by height. More pixels capture more detail, and the total is often summarized in megapixels, or millions of pixels.

Full HD, 1920 by 1080, is about 2.1 megapixels. Multiplying 1920 by 1080 gives 2,073,600 pixels, which rounds to 2.1 million, or 2.1 MP.

Not on their own. Megapixels set how much detail an image can hold, but quality also depends on sensor size, lens, lighting, and processing. A lower megapixel photo can look better than a higher one.

It depends on the print size. Larger prints need more pixels to stay sharp. A rough guide is that more megapixels allow bigger prints, but viewing distance also affects how sharp a print needs to be.

Resolution is the total pixel count, the detail. Aspect ratio is the shape, the width-to-height relationship. Images can share a megapixel count but have different aspect ratios.

Yes. Cropping removes pixels from the edges, so the megapixel count drops. Starting with a higher resolution gives you more room to crop while keeping enough detail.

No. The calculation runs in your browser and nothing you enter is stored or sent anywhere, unless you choose Save, which keeps the result only on this device.

• Image resolution (general reference).
• Pixel and megapixel (general reference).