top off water

[lestershy]

I recently made an oatmeal stout and got an OG reading of 1.080. I proceeded to add my top off water and put it away. I just realized that my OG is based on the volume before topping off. Does anyone know how much of a change in gravity there would be after adding about 3/4 gallon of water? Would it really change that much?
Thanks

 

[JewBrew]

need some info first how many gallons total do you have after adding the water

 

[BigB]

If you had a starting volume of 4.25 gallons of 1.080 wort and added .75 gallons of water, you would have an OG of 1.068.

 

[lumpher]

need some info first how many gallons total do you have after adding the water

that's right. we have to know how many gallons you started with

 

[lestershy]

need some info first how many gallons total do you have after adding the water

Sorry for the lack of info.
I started with 4 1/4 gallons and added 3/4 gal to make it a 5 gal batch total.

 

[lestershy]

If you had a starting volume of 4.25 gallons of 1.080 wort and added .75 gallons of water, you would have an OG of 1.068.

Great. Thanks!