# How to convert inches into pixels?

This is a discussion on How to convert inches into pixels? within the A Brief History of Cprogramming.com forums, part of the Community Boards category; I am just working on a pic, but I don't know how to convert inches into pixels. I have a ...

1. ## How to convert inches into pixels?

I am just working on a pic, but I don't know how to convert inches into pixels. I have a certain size for the pic that is in inches. And I am using adobe imageready and it only has the pixels option.

THanks

2. Thanks Rod,

I know, I searched the google but for some reason couldn't find it.

Thanks again

3. Not a problem, i searched for

"convert pixels to inches"

Whenever you need a conversion, start your search string with convert it works very well.

4. p = DPI * i

p = number of pixels
i = number of inches
DPI = dots per inch.

Perhaps this isn't what you're looking for. I'm not sure I understood.

5. Well, the difficult part is finding the DPI. It differs from device to device. And sometimes there's just no way to get accurate information. Which is why applications like the Gimp need to be calibrated.

6. From your own programs on Windows, you can use SetMapMode() to change the mapping between logical units and display units. By default, the map mode is 1 to 1, i.e. one logical unit is equal to one pixel, but yu can change the scaling to work in millimeters or inches, (well, fractions of).

7. ppi varies a lot....a pretty standard ppi is 72, I believe. So inches*72 could get you the amount of pixels, in theory...as long as you had a ppi of 72. But it can vary between images.

8. It varies between screens, not images really.
Finding out yours is pretty simple. Measure the width of your screen, divide by your horizontal resolution.