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Water-to-Grain Ratio Calculator

Calculate mash-in water from dry-grain weight and a chosen ratio. Convert between lb with US qt/lb and kg with L/kg without mixing volume and mass units.

Use this result well

Inputs that matter
Grain and ratio units, Dry grain (lb), Water ratio (US qt/lb), Dry grain (kg), and 1 more
Output to expect
Mash-in Water from Grain and Ratio
  • Check the units and required inputs before comparing results.
  • Keep the assumptions with a copied result so you can reproduce the calculation later.
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Reference & details

How it works

Multiply quantities with matching units

Pounds multiplied by US liquid quarts per pound gives US quarts. Kilograms multiplied by liters per kilogram gives liters. This computes the initial water addition, not wort yield.

Water (US qt) = grain (lb) × ratio (US qt/lb); water (L) = grain (kg) × ratio (L/kg)

Source: Propagate Lab: brewing-water planning

Convert volume ratios explicitly

One US liquid quart is 0.946352946 liters; one avoirdupois pound is 0.45359237 kilograms. Therefore 1 US qt/lb is approximately 2.086351 L/kg. A qt/lb ratio cannot be multiplied by kilograms and treated directly as liters.

L/kg = (US qt/lb) × 0.946352946 / 0.45359237

Source: NIST Guide for the Use of SI

Keep process losses separate

Grain absorption, mash-tun dead space, sparge water, evaporation and transfer losses are not included. The ratio does not establish temperature, pH or conversion efficiency.

Updated: September 2026

Example Scenarios

Calculate mash-in water from dry-grain weight and a chosen ratio. Convert between lb with US qt/lb and kg with L/kg without mixing volume and mass units.

Compare physically equivalent US and metric inputs before using the result.

Save the calculation with units and the recipe or measurement assumptions.

Common Mistakes to Avoid

Mixing qt/lb with kilograms

Convert the ratio to L/kg before multiplying by kilograms.

Treating strike water as wort yield

Account for absorbed and retained water, sparging and later process losses separately.

FAQ

No. It is mash-in water only. Plan sparging and later losses separately.

Not in the US unit mode. Convert the grain and ratio to kilograms and liters per kilogram first.

Only under an additional water-density assumption. This tool accepts volume per grain mass, not mass per mass.

18 US liquid quarts, equal to 4.5 US liquid gallons or 17.034353028 liters.

About Water-to-Grain Ratio Calculator

Plan the water mixed with dry grain at the start of a mash. Choose matched units, enter the grain bill and ratio, and keep total brew-day losses separate.