Brewing Water Volume Calculator

Calculate strike, sparge, pre-boil, and total brewing water. Adjust grain absorption, losses, boil-off, and shrinkage. Build reliable water plans for every homebrew batch size.

Calculator Input Form

Reset

Formula Used

Boil-off loss = Boil-off rate × Boil time ÷ 60

Cool post-boil need = Target fermenter volume + Trub loss + Kettle dead space - Top-up water

Hot post-boil volume = Cool post-boil need ÷ (1 - Cooling shrinkage ÷ 100)

Pre-boil volume = Hot post-boil volume + Boil-off loss

Strike water = Grain weight × Mash thickness

Grain absorption loss = Grain weight × Absorption rate

Total brewing water = Pre-boil volume + Grain absorption loss + Mash tun dead space

Sparge water = Total brewing water - Strike water

How To Use This Calculator

  1. Select metric or US units.
  2. Enter your target fermenter volume.
  3. Add grain weight and mash thickness.
  4. Enter absorption, boil-off, and system loss values.
  5. Add cooling shrinkage and top-up water if needed.
  6. Press the calculate button.
  7. Review strike water, sparge water, and total water.
  8. Download the result as CSV or PDF.

Example Data Table

Batch Type Target Volume Grain Weight Boil Time Estimated Total Water
Pale Ale 20 L 5 kg 60 min About 33 L
Strong Stout 20 L 7 kg 75 min About 39 L
Small Lager 12 L 3 kg 60 min About 22 L

Brewing Water Volume Calculator Guide

A good brew day starts with a clear water plan. Malt absorbs water. Boiling removes more. Transfers leave liquid behind. Cooling also shrinks hot wort. This calculator brings those losses together. It helps you plan strike water, sparge water, pre-boil volume, post-boil volume, and total water.

Why Water Planning Matters

Too little water can reduce kettle volume. It can raise gravity higher than expected. Too much water can dilute wort and extend boiling time. A measured plan keeps the recipe stable. It also helps repeat the same beer later. Consistent volume makes gravity, bitterness, and color easier to control.

Core Inputs

The calculator uses target batch volume, grain weight, mash thickness, absorption rate, boil time, boil-off rate, trub loss, equipment loss, shrinkage, and top-up water. Each value represents a real brewing stage. You can use metric or US units. The tool converts values internally, then shows results in your chosen unit.

Strike And Sparge Balance

Strike water is the hot water mixed with crushed grain. Mash thickness decides its size. Sparge water rinses sugars from the grain bed after mashing. The calculator subtracts strike water from total mash-side needs. If strike water already covers the need, sparge water becomes zero.

Brewing Maths Behind The Result

Pre-boil volume starts from the cool volume needed after boiling. The tool adds kettle losses, then adjusts for cooling shrinkage. It then adds boil-off. Total brewing water adds grain absorption and mash tun losses. Top-up water reduces the kettle requirement because it is added later.

Practical Use

Measure your system during several brew days. Update absorption, boil-off, and dead space values with your own observations. This makes the answer more accurate. Keep a small buffer for hops, heavy grain bills, or long whirlpools. Use the export buttons to save a record. Compare planned and actual volumes after each batch. Over time, your water estimates will match your brewing setup closely.

Record Keeping

Save one line for every brew. Note the measured pre-boil volume. Note the chilled fermenter volume too. Small differences show where losses changed. Seasonal humidity, stronger burners, and wider kettles can change boil-off. Better records make the calculator smarter for your next recipe. Use it before heating water.

Frequently Asked Questions

What does total brewing water mean?

Total brewing water is the complete water amount needed before brewing starts. It includes strike water, sparge water, grain absorption, boil-off, and equipment losses.

What is strike water?

Strike water is the heated water mixed with crushed grain. Its amount depends on grain weight and mash thickness.

What is sparge water?

Sparge water rinses sugars from the grain after mashing. This calculator estimates it after strike water and losses are considered.

Why is grain absorption important?

Grain holds water after mashing. Ignoring absorption can leave your kettle short before boiling starts.

Why does cooling shrinkage matter?

Hot wort contracts as it cools. Shrinkage adjustment helps estimate the hot post-boil volume needed for the correct cooled volume.

Can I use this for extract brewing?

Yes, but set grain weight and absorption low or zero. Then focus on boil-off, losses, target volume, and top-up water.

What is a normal boil-off rate?

Boil-off changes by kettle size, burner power, weather, and boil strength. Measure your own system for the best value.

Why is my sparge water zero?

Sparge water becomes zero when strike water already covers the calculated need. Reduce mash thickness if you want a separate sparge step.

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Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.