My photoshop files are too large

[Yuri Kai]

For some reason photoshop is making my files excessively large, around 700 mb to 1 gb.

All I did was create an A3 file and insert a 2mb picture inside of it, and suddenly the file had 700 mb for some reason. Is this normal?

[D Fosse]

Photoshop works with pixels, not sizes. How many pixels w x h ?

"A3" doesn't mean anything in itself, but if you tell us the ppi number (pixels per inch), the pixel size can be calculated. For instance, if it's 300 ppi, the pixel size will be 3508 x 4961 pixels.

Saved as a flat PSD that should be somewhere around 100GB. So your file does seem rather large. What's the ppi?

[Stephen Marsh]

If you go to File > File Info and then the Raw Data tab, do you see a message like this?

[Yuri Kai · Accepted solution]

Thanks everyone for the replies, I've figured out what the problem was. For some reason my image was set to pixels per centimeter, not pixels per inch. After changing that and resizing it, it went down from 1.5 gb to 300 mb. Problem solved!

[D Fosse]

OK, but you should be very careful with resampling files like that. You should always change ppi with "resample" unchecked first, then see if you have sufficient print size at that ppi.

Resampling smaller is fine, we all do that. But resampling bigger usually just causes unnecessary damage to the file. It's normally not necessary or desirable.

It's usually much better to print a 200 ppi file as-is, than to resample it up to 300.