# 1 cm corresponds to the number of kilometers

## How many pixels are there in 1 cm - this is how you calculate it

The question of how many pixels there are in 1 cm of an image is particularly interesting if you want to transfer an image or a design to a specific output medium. Above all, it is important which resolution is required for the desired process, for example high-quality image printing.

### Calculating with pixels - you need to know this

• In the digital representation of images, pixels are the smallest unit. The resolution of image files traditionally refers to the unit "inch", where 1 inch corresponds to 2.54 cm. The resolution is therefore usually given in "dpi" (dots per inch).
• To print, you must first select the paper size of your document.
• The greater the number of pixels that can be displayed on 1 cm of the respective image, the greater the resolution. Image files that you want to print out in high quality and on good paper and perhaps in large format should have a resolution of 300 dpi.
• The number of pixels per inch depends on the printing process.
• For test prints, a printout on a smaller paper format is usually advisable, purely for cost reasons. In classic layout programs - such as Indesign - this is done automatically by setting a percentage value for the printout.

### Calculate how many pixels are 1 cm

Typical, often unsightly effects arise in the print image, which depend on how many print raster points are required to represent a pixel. If the pixel grid is larger than the print grid, it will be visible in the print. To avoid this, you need to find the correct factor to convert.

• Your goal in the correct adaptation of your image file must be that the pixel grid is smaller than the print grid. Usually you have to work with a factor between 1.4 and 2.
• Find out which raster should be used for printing and calculate the appropriate image size using the formula "Print raster times quality factor equals image resolution". A printing raster of 60 raster lines per centimeter corresponds to 152.4 raster lines per inch.
• As a rule of thumb, you can scan your image at twice the resolution that you ultimately want to print it at.