Pre-boil G 1.040 @ 78F (7 gallon) = 1.042 OG 1.055 @65.1F = 1.055 Got 5 gallons out of boil kettle. Added 1/2 gallon water. OG 1.050@65.7F = 1.050 Ouch ... why so high? Figured it out. Recipe asked for 5lb Maris Otter Malt extract. I used 6lb. Oops. 12/27/2016 : FG 1.011 @ 65.5F = 1.011. 77% attenuation for 5.1% ABV.
Based on boiling 7.00 gallonsliters at 1.042 for 90 minutes, this will decrease your wort by 0.00 gallonsliters, bringing your after boil OG to 1.042. You were planning on an OG of 1.042 so you are right on track. Nice job!