Menu Icon

Looking for homebrewing gift ideas? Check out our previous gift guides here or here!
Also, if you enjoy BrewUnited, please consider doing your Amazon shopping via our affiliate link!

Homebrew Dad's Dilution and Boiloff Calculator

It never hurts to have
another hydrometer on hand!
Don't guess about your gravity. Know what it is.

Use the utilities below to calculate your gravity after dilution or boiloff, your gravity after blending beers, or the volume you need to achieve a desired target gravity.

Please note that these utilities are unit-neutral; you may enter your volumes in gallons, liters, quarts, etc. They do, however, assume that you are using the same unit of measurement for each volume. So, for instance, if you are diluting a five gallon batch of beer with a half gallon of water, be sure to input the volumes as "5" and ".5", respectively.

Dilution Calculator

Use the following calculator to give the adjusted gravity after dilution. Unlike some tools, which allow you to input only your beer and the amount of water you are diluting your beer with, this calculator allows you to input one additional volume of liquid, as well as to specify its gravity of all three liquids. Most often, this would be useful if trying to determine the gravity of a beer if you were topping off with water, then adding an additional amount of liquid starter (which will certainly have a gravity above that of water's 1.000).

You may also use this calculator to yield the correct gravity of a blended beer, since each of the three variables allow the input of both volume and gravity.

Volume 1 - typically, your wort/beer
Gravity 1
Volume 2 - typically, top off water (or your second beer)
Gravity 2
Volume 3 - typically, your starter (could be a third beer)
Gravity 3

Boiloff Calculator

Use the following calculator to determine what the gravity of your wort will be once you boil it down to the desired volume.

Original Volume
Original Gravity
Final Volume

Target Volume Calculator

Use the following calculator if you know your desired target gravity, but need help figuring out the volume needed (either through dilution with plain water or through boiloff) to achieve it.

Original Volume
Original Gravity
Desired Gravity