What losses should I account for?

Main losses: grain absorption (~1.04 L/kg), boil-off (3-5 L/hr), trub/hop debris (0.5-2L), dead space in kettle/mash tun (0.5-2L each). Track your actual losses over several brews to dial in your system.

What is a typical boil-off rate?

Most homebrewing systems lose 3-5 litres per hour to evaporation. Wider kettles lose more than tall, narrow ones. Electric kettles tend to lose less than gas-fired ones. Measure yours by noting volume before and after a 60-minute boil.

Do BIAB brewers need sparge water?

Full-volume BIAB uses all water in the mash — no sparge needed. Some BIAB brewers do a quick dunk sparge to improve efficiency. In that case, the sparge volume is typically 5-10L.

How do I calculate total water for a brew day?

Total water = mash water + sparge water. Mash water = grain weight x water ratio. Sparge water = batch size + boil-off + grain absorption - mash water. This calculator helps you plan to avoid running short or having excess.

What about no-sparge or BIAB brewing?

For no-sparge or BIAB, use all your water in the mash. Total water = target pre-boil volume + grain absorption. The water-to-grain ratio will be higher (typically 3.5-5.0 L/kg), which actually improves conversion efficiency in most cases.

BrewCalcs

Water Volume Calculator — Total Brew Water

Calculate total water needed including mash, sparge and all losses.

Batch Size (into fermenter)

Volume of your batch

Grain Weight

Total weight of grain in your recipe

Boil Time

Duration of the wort boil

Boil-Off Rate

Rate value for this calculation

Trub/Hop Loss

Enter the trub/hop loss

Equipment Dead Space

Running pace

How We Calculate This

Water Volume Calculation

Total Water = Batch Size + Boil-Off + Trub Loss + Grain Absorption + Equipment Loss

Mash water is calculated at 2.6 L/kg. Sparge water is the remainder (Total - Mash). For BIAB, all water goes into the mash.

Frequently Asked Questions

Related Calculators

Strike Water Calculator

Calculate strike water temperature for your target mash temperature.

Mash Temperature Calculator

Determine resulting mash temperature from grain and water inputs.

Sparge Water Calculator

Calculate sparge water volume for your batch size and grain bill.

Water Chemistry Calculator

Calculate salt additions for target water chemistry profiles.

pH Adjustment Calculator

Calculate acid or base additions to hit your target mash pH.

Last updated: 2025-02-20

All calculations are estimates. Always verify values and adjust based on your equipment and ingredients.