Reading the Delta-V map

[AlpacaMall]

Are dV values on the map vacuum dV, or are they however much dV we can actually get? (for example, if I have a first stage that gets 2500 dV in vacuum but only 1500 at sea level, should I use the atmosphere value or vacuum value?)

[OHara]

That community delta-v map gives numbers as vacuum delta-v.   So you include the 2500m/s for for stage when comparing to that map. 

That map quotes the higher vacuum numbers based on players' experience with typical rockets.  So, it is a little sloppy.  But, the first part of the launch in deep atmosphere is short enough that the sloppy estimates are very useful in practice.