Dilution Calculator
Water spreads the same sugar over more volume. Add the gap between your current and target volume.
Overshot your target gravity? The calculator above tells you exactly how much water to add to bring it back down. Enter your current volume and gravity, set your target, and it gives you the water volume needed.
How We Calculate It
Sugar doesn't disappear when you add water. The total gravity points stay constant. Water to add = total volume − current volume.
This is basic conservation of mass. The gravity points (sugar content) in your wort don't change when you add water — you're just spreading them across a larger volume. It's exact, not an approximation. If your gravity is too low instead, boil it down to concentrate it.
How much water do I add to lower gravity?
Water to add = current volume × (current points ÷ target points − 1). For 20 L at 1.060 aiming for 1.050: 20 × (60/50 − 1) = 4 L.
Is dilution exact or an estimate?
It's exact for gravity, because it's conservation of sugar (gravity points). The only real-world fudge is that volumes aren't perfectly additive, and that error is negligible at homebrew scale.
Can I dilute after fermentation?
You can, but diluting finished beer also waters down flavor, bitterness, and carbonation. It's usually better to correct gravity before or during the boil.
What if my gravity is too low instead?
You can't dilute up. Boil longer to evaporate water (see the boil-off calculator) or add dry or liquid malt extract to raise gravity.