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Generated on: July 20, 2026 at 09:33 PM

Megapixel & Print Size Calculator

Inputs

Width6,000
Height4,000
Print resolution300

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Computer Science

Megapixel & Print Size Calculator

Enter an image width and height in pixels to find its megapixel count, then choose a print resolution to see how large it can be printed in inches or centimetres. Useful for cameras, scans, and preparing files for print.

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Image Resolution

≥ 1

Results

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Megapixels

MP = \dfrac{w \times h}{1{,}000{,}000} = \dfrac{\left(6,000\right)\left(4,000\right)}{1{,}000{,}000} = ?

Print Size

W = \dfrac{w}{r} = \dfrac{6,000}{300} = ?\,\text{cm}
H = \dfrac{h}{r} = \dfrac{4,000}{300} = ?\,\text{cm}

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Megapixels & Print Size

A digital image is a grid of pixels. Two numbers describe that grid completely — its width and height in pixels — and from them the megapixel count and the largest sharp print both follow with simple arithmetic.

Megapixels

MP=w×h1,000,000MP = \frac{w \times h}{1{,}000{,}000}

where ww and hh are the width and height in pixels. The prefix mega means million, so a megapixel is one million pixels. Multiplying the two sides of the grid gives the total pixel count; dividing by a million expresses it in megapixels.

Worked example. A 6,000 × 4,000 image:

MP=6,000×4,0001,000,000=24,000,0001,000,000=24 MPMP = \frac{6{,}000 \times 4{,}000}{1{,}000{,}000} = \frac{24{,}000{,}000}{1{,}000{,}000} = 24 \text{ MP}

This is the resolution of a typical 24-megapixel camera in its standard 3:2 aspect ratio.

Print resolution is measured in dots per inch (dpi). When one image pixel maps to one printed dot, the printed length along each side is the pixel count divided by the dpi:

W=wr,H=hrW = \frac{w}{r}, \qquad H = \frac{h}{r}

with rr the print resolution. At 300 dpi the 6,000 × 4,000 image above prints:

W=6,000300=20 in≈50.8 cmW = \frac{6{,}000}{300} = 20 \text{ in} \approx 50.8 \text{ cm} H=4,000300=13.33 in≈33.9 cmH = \frac{4{,}000}{300} = 13.33 \text{ in} \approx 33.9 \text{ cm}

The same file printed at 150 dpi would be twice as wide and tall — roughly 40 × 26.7 inches — because the same pixels are spread over a larger area.

Maximum print size by megapixels

The table below shows the largest print at 300 dpi for common resolutions, assuming a 3:2 aspect ratio.

MegapixelsPixelsPrint at 300 dpi
2 MP1,728 × 1,1525.8 × 3.8 in
12 MP4,240 × 2,83214.1 × 9.4 in
24 MP6,000 × 4,00020 × 13.3 in
50 MP8,660 × 5,77328.9 × 19.2 in
100 MP12,247 × 8,16540.8 × 27.2 in

Choosing a print resolution

300 dpi is the usual target for photographs and anything viewed up close, because it sits near the limit of detail the eye resolves at normal reading distance. Larger prints are viewed from farther away, so they tolerate lower resolutions: posters look fine at 150 dpi, and billboards are often printed below 50 dpi. Lowering the dpi lets the same pixel count cover a bigger area, trading fine detail for size.

Megapixels and image quality

A higher megapixel count records more detail and supports larger prints or tighter crops, but it does not guarantee a better photograph. Lens sharpness, sensor size, dynamic range, and lighting matter as much or more. Past the point where the print no longer benefits, extra megapixels mainly enlarge the file.

To turn a physical screen size and resolution into pixel density, see the PPI / DPI Pixel Density Calculator. To estimate how much storage an uncompressed image of a given resolution needs, the Image File Size Calculator applies the same pixel count to a bit depth.

Frequently Asked Questions (FAQ)

How do you calculate megapixels from resolution?

Multiply the image width in pixels by its height in pixels, then divide by 1,000,000. For example, a 6,000 × 4,000 image is 24,000,000 pixels, which is 24 megapixels. The "mega" prefix simply means million, so one megapixel equals one million pixels.

Do more megapixels mean a better photo?

More megapixels capture more detail and allow larger prints or tighter crops, but they are not the whole story. Lens sharpness, sensor size, dynamic range, and lighting all affect image quality. Beyond a certain point extra megapixels mainly add file size, so the right count depends on how large you intend to print or display the result.

How is print size calculated from pixels and dpi?

Divide the pixel count along each side by the print resolution in dots per inch. A 6,000-pixel-wide image at 300 dpi prints 6,000 ÷ 300 = 20 inches wide, or about 50.8 cm. Lowering the dpi spreads the same pixels over a larger area, increasing the print size at the cost of fine detail.

What dpi should I use for printing?

300 dpi is the common target for photo prints and anything viewed up close, because it is around the limit of detail the eye resolves at normal reading distance. Large posters and banners viewed from several feet away print fine at 150 dpi or even lower, while fine-art reproduction sometimes uses 600 dpi. Choosing a higher dpi yields a smaller maximum print size for the same pixel count.

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