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Water-to-Spirit Dilution Calculator

From your spirit's volume, ABV, and the target ABV, work out exactly how much water or ice to add. See the total volume, final ABV, and spirit-to-water ratio at a glance.

Input

Enter the volume and ABV of your spirit plus the target ABV you want, and we'll work out how much water or ice to add. Bear in mind that melting ice dilutes it further, so adjust to taste.

ml
%
%

Result

Water / ice to add

70ml

Pure alcohol (approx.):about 9.6 g

Total volume

100 ml

Final ABV

12.0 %

Spirit : water ratio

1 : 2.3

How it works

  • From the spirit volume, the spirit's ABV, and your target finished ABV, this tool calculates how much water (or ice) to add.
  • The formula is: water to add (ml) = spirit volume (ml) x (spirit ABV / target ABV - 1). For example, to cut 30 ml of 40% whisky down to 10%, you need 30 x (40 / 10 - 1) = 90 ml of water.
  • Set the target ABV lower than the spirit's ABV. If the target equals or exceeds the spirit's ABV, the required water amount drops to zero or below and cannot be calculated.
  • It also shows the finished total volume (spirit + water) and the approximate spirit-to-water ratio. Allowing for melting ice, mixing it slightly stronger and adjusting is a good approach.
  • The amount of pure alcohol is set by the spirit's volume and ABV; diluting with water does not change that total. Be careful not to overdo it.
  • This tool provides estimates only. Drink responsibly, and avoid alcohol if you are underage, pregnant, nursing, or about to drive.