# Dilution Calculator

Wort dilution uses the principle that gravity points are conserved when water is added: points × volume stays constant. Given a current gravity and volume and a target gravity, the water needed is V₁ × (OG − 1) / (target − 1) − V₁. The same formula works for topping up a short boil, diluting a parti-gyle first runnings, or adjusting a beer that finished too strong.

Overshot your gravity? This tells you exactly how much water brings it to where you want it.

HTML version: https://brewgravity.com/calculators/dilution/

## Inputs

- **Current gravity** (min 1, step 0.001) — default: 1.080
- **Current volume (L)** (min 0.1, step 0.5) — default: 19
- **Target gravity** (min 1, step 0.001) — default: 1.050

## Outputs

- **water**: Water to add
- **final**: Final volume
- **plato**: Target in °Plato

## FAQ

### Can I dilute after fermentation?

Yes — adding boiled, cooled water to a finished beer lowers the gravity (and ABV) without restarting fermentation. It is a common technique for bringing a too-strong beer into style range, and commercial breweries do it routinely as "high gravity brewing."

### Does dilution affect bitterness?

Yes. IBU scales with volume the same way gravity does, so diluting a 19 liter batch to 23 liters reduces both gravity and bitterness by the same proportion. If you are diluting significantly, recalculate your IBU target.

### What about parti-gyle brewing?

A parti-gyle splits the runnings into a strong first wort and a weaker second wort. This calculator can tell you how much water to add to the second runnings to hit a target gravity for the smaller beer.

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Source: https://brewgravity.com — Free dilution calculator giving the water volume needed to reduce wort or beer from one specific gravity to another, using gravity-point conservation.