Not sure about the -500 series (which I don't get to fly), but working from memory: this week on an ATR42-300F on CDG-WAW, my PLOGs were showing about 1,600 kg
trip fuel, 2,400
block fuel (round figures) for a 700nm trip planned at FL180/190 (although we negotiated FL200/210 with ATC). Flight times were about 3h35 westbound (strongish 45-50 kt headwinds all the way no matter which level) and 3h00 eastbound (for the same reason).
At FL200-210 in ISA conditions the fuel burn was around 240 kg/eng/hour. Taking into account the weather etc. we typically rounded up the standard fuel to 2,600-2,800 kg depending on expected payload.
Hope that helps!
Cheers
