Gainward PCX GTX770 - Enough space in case

Hi community!
I was considering to buy the Gainward PCX GTX770. But I'm really not if there's enough space in my case. Are there any standard sizes? The graphics card is 40 x 25 x 6 cm.
I've tried to open the case and see if it should fit. But sizes like that makes me insecure. Any tips/tricks to see if it will fit?
André

If a measuring tape won't work than you can check sizes in the computer manual, those ready made computers can be various and not always standard sizes. That video card is pretty long so see in the computer manual for space for Full size video card.