If you want to add water to achieve a desired gravity (or boil it to remove it), this will show you how much you need to add/remove to achieve the desired gravity.

• Wort Volume: current wort volume
• Current Gravity: current gravity
• Target Gravity: the target gravity.

If you want to add water to your wort, this will tell you the effect of the water on the gravity.

• Wort Volume: current wort volume
• Current Gravity: current wort gravity
• Target Volume: target wort volume. e.g. if you’re adding 5 litres to 20 litres, put 25 here.