Brewed today and hit an OG of 1.08....@ 4 gallons. I must have miss measured somewhere along the way. I added 1 gal of water....what my new OG? Target OG was 1.065. Thanks!

1.064

1.080 for math purposes turns into 80. 80x4gal=320 gravity points of sugar. If you have that amount of sugar in 5 gallons it would be 320/5 which equals 64 like sketerbuck said. So you'd have 1.064. You understand the math now?

Cool thanks guys!!