There are several free image editors available if she doesnt have one. The screenshots are from Photoshop or Elements, but I would think any real image editor would have a similar display. Rest assured that the DPI setting has changed, which will ONLY IMPACT the printers/software combination that actually use the DPI info.Ī real image editor will give you the relationship without the math and probably make it a little more clear. Enter the value you want and then press the button, and Save the picture. There you will see the 'Resolution' fields.

To use IrfanView to change the DPI, just open the picture, and then press the 'i' key. (You can't make it a fraction - like 409.6 - so make it 409 or 410.) Change it to 410 if you want something closer. Just use IrfanView to change the DPI to 400 (which is close enough, unless you want something more exact. If you are desiring a particular final hardcopy size with a DPI setting to match, just take the number of pixels you have for one dimension (for example horizontal) and divine by the number of inches you want that printout to be.įor example: if you have a picture with 2048 pixels across, and you want it to print in 5 inches, just divide 2048 by 5, or 409.6.

If you want to use an image editor, such as IrfanView, you can use it to change the DPI setting to whatever number that you want. The DPI (Dots Per Inch) info is nothing but a single entry (well, actually two, one for horizontal and one for vertical, but usually they are the same value).

How to find dpi of jpg