How many megapixels do I need for a print?

For a good 12 × 8 inch print at 300 DPI you need about 8.6 MP. Large prints viewed from a distance need far fewer.

What is a 3:2 aspect ratio?

The classic 35mm frame shape, which is why it prints perfectly to 6 × 4 inches.

Image Resolution Calculator – Formula & Examples

DPI	Inches	Centimetres
72	55.56 × 41.67	141.1 × 105.8
150	26.67 × 20	67.7 × 50.8
200	20 × 15	50.8 × 38.1
300	13.33 × 10	33.9 × 25.4
600	6.67 × 5	16.9 × 12.7

DPI

Inches

Centimetres

55.56 × 41.67

141.1 × 105.8

150

26.67 × 20

67.7 × 50.8

200

20 × 15

50.8 × 38.1

300

13.33 × 10

33.9 × 25.4

600

6.67 × 5

16.9 × 12.7

About the Image Resolution Calculator

An image’s pixel dimensions decide three things at once: how many megapixels it holds, what shape it is, and how large it can be printed before the pixels become visible. This calculator works all three out and shows the aspect ratio in its simplest whole-number form.

Also known as: image size calculator, megapixel calculator, photo resolution, pixel dimensions, aspect ratio calculator.

How to use this calculator

Enter width, height, print resolution.
The result updates instantly as you type — press Calculate (or Enter) at any time.
Review the breakdown shown under the main result.
Use Copy result or Share to save the answer or send a link with your inputs.

Formula

megapixels = width × height ÷ 1,000,000

Worked example

Using the values pre-filled in the calculator above:

Width = 4,000 px
Height = 3,000 px
Print resolution = 300 DPI

the calculator returns:

Megapixels: 12 MP
Total pixels: 12,000,000
Aspect ratio: 4 : 3
Ratio as a decimal: 1.3333

Image Resolution Calculator

Enter values