Download BeerSmith and set all of the settings to what you're doing (partial/all grain, pre-boil volume, equipment, etc). Enter your recipe into there. 5% is way too low for an IPA.
What you're going to want to do is up the grains or extract as well as the bittering hops. BeerSmith will give you a great approximation of IBUs and OG if you have everything set correctly. The alcohol comes from the malt but in order to not end up with a sweet beer, you need to up the bittering hops as well.
I try to keep my extract, whether it be LME or DME, at around 60% of my malt when doing partial mash. In other words, 60% would be LME/DME while the other 40% are my grains.