Original gravity · brew-day guide
Original gravity too high? Work out the dilution.
Before fermentation, use your measured wort volume and temperature-corrected specific gravity to estimate the water needed to reach your target.
Try the wort dilution calculator
This estimates volume from conserved gravity points. It assumes water contributes no extract and volumes add together. Use temperature-corrected readings from the same sample conditions.
Worked example: 18 L at 1.060, target 1.050
Current wort holds 18 × 60 = 1,080 point-liters. At 50 gravity points, the final volume is 1,080 ÷ 50 = 21.6 L. The estimated addition is 3.6 L of water.
Final volume = current volume × (current SG − 1) ÷ (target SG − 1)
Water to add = final volume − current volume
Use the same calculation offline on iPhone
- Open Homebrew Calculator: Brew Day and choose Tools → Gravity fix.
- Enter your current wort volume, current SG and target SG. Keep your units consistent.
- Read the suggested water addition. Add carefully, mix, and measure again rather than treating an estimate as an exact result.
- Save the measurement and calculation with your tracked batch so the next brew has a useful reference.
What if gravity is too low?
Dilution only lowers gravity. A lower current SG needs a different adjustment; the app also reports evaporation volume and missing point-liters. This calculator does not recommend a fermentation or packaging decision.
Can I use a refractometer after fermentation?
Alcohol changes the reading. Use the app’s fermented refractometer correction with the original Brix and current Brix instead of entering an uncorrected post-fermentation reading here.
What does the app cost?
Recipes are unlimited. The first tracked brew is free. Lifetime or Monthly Pro unlocks unlimited tracked sessions; the purchase screen shows the current local price. Monthly renews until cancelled.