Dilution & Boil Off Calculator
Calculate how much water to add to hit your target gravity, or estimate your post-boil volume and gravity concentration from evaporation.
Dilution Calculator
Your wort is too strong? Calculate how much water to add to reach your target gravity.
Water to Add
1.63 gal
New Total Volume
8.13 gal
Boil Off Calculator
Estimate your post-boil volume based on your boil time and evaporation rate.
Typical: 1.0–1.5 gal/hr
Evaporation
1.50 gal
Post-Boil Volume
5.50 gal
Post-Boil Gravity
1.076
if pre-boil = 1.060
Tips
Boil off rate varies by kettle diameter, burner strength, and lid position. Most homebrewers lose 1.0–1.5 gallons per hour on a vigorous, uncovered boil.
Dilution uses the formula: V1 × G1 = V2 × G2. Always add cool, sanitized water (pre-boiled is ideal) to avoid contamination.
Measure your boil off rate by marking your kettle before and after a boil. Knowing your specific rate makes all future brew days more predictable.