How It Works
This calculator works in 4 steps.
Enter the current gravity
Type the specific gravity or °Plato reading.
Enter the current volume
Type the wort volume in gallons or liters.
Enter the target
Type the target gravity, or the volume after adding water.
Read the result
The calculator returns the new gravity or the water to add, plus total gravity points.
The Formula
The formula keeps total gravity points constant across the dilution.
GP = (SG − 1) × 1,000GP₁ × V₁ = GP₂ × V₂V_water = V₁ × (GP₁ / GP₂ − 1)°P ≈ GP / 4- SG:
- Specific gravity
- GP:
- Gravity points
- V₁ / V₂:
- Volume before and after adding water
5 gallons at 1.060 (60 points) diluted to 6 gallons gives 60 × 5 / 6 = 50 points, or 1.050.
Conversion Table
The conversion table gives the new gravity for 6 wort volumes after adding water (volumes in any shared unit).
| Original gravity | Volume before | Volume after | New gravity | Total points (before → after) |
|---|---|---|---|---|
| 1.060 | 5 | 6 | 1.050 | 300 → 300 |
| 1.080 | 20 | 23 | 1.070 | 1,600 → 1,600 |
| 1.050 | 10 | 11 | 1.045 | 500 → 500 |
| 1.070 | 5 | 5.5 | 1.064 | 350 → 350 |
| 1.090 | 19 | 23 | 1.074 | 1,710 → 1,710 |
| 1.045 | 6 | 6.5 | 1.042 | 270 → 270 |
What Is the Brewing Dilution Calculator?
The Brewing Dilution Calculator is a tool that models how adding water to wort changes its volume and specific gravity, using the conservation of gravity points. Gravity points are the specific gravity minus 1, times 1,000, so 1.060 is 60 points.
Brewers dilute wort that comes in above target gravity, or top up a short batch. Total gravity points (points × volume) stay constant when water is added. The calculator returns the new gravity, or the water needed to reach a target gravity, in gallons or liters, and converts gravity to degrees Plato (°P) for brewers who work in Plato.
Common Uses
There are 5 main uses of this calculator.
Hitting target original gravity
Brewers dilute over-gravity wort before pitching yeast.
High-gravity brewing
Breweries brew strong wort and dilute to final strength.
Topping up fermenters
Homebrewers top up short batches with water.
Extract brewing
Brewers dilute concentrated extract boils.
Recipe planning
Brewers plan boil-off and top-up volumes.