This is a rule of thumb for non-short distances, full load 800:
Taxi fuel, say 200kg
+
Tripfuel (Kg) = Air distance (Nm) x 6
+
5 % contingency
+
fuel you want to (ideally) land with to cover alternate & final reserve fuel, say 2000kg.
Your example (no wind):
Taxi = 200kg
Tripfuel= 2300 x 6 = 13800kg
Contingency = 690kg
rest= 2000kg
-------------------------------
16690kg
Again, this is a rule of thumb for a gross crosscheck. Never use this for actual planning :-)