Alcohol Dilution Calculator

Created by Łucja Zaborowska, MD, PhD candidate
Reviewed by Bogna Szyk and Jack Bowater
Last updated: Jan 03, 2023

Our alcohol dilution calculator allows you to efficiently compute amount of alcohol and water needed for any homemade alcohol solutions. It doesn't matter if you're trying to convert 91 isopropyl alcohol to a 70% solution or distilling your own fruity liquor – this tool will be helpful in all possible scenarios.

Click the advanced mode for the alcohol contraction🍾

Remember that our calculators work in all directions – we'll help you with whatever you're trying to calculate!

The article below will explain the theory of alcohol dilution, present the alcohol dilution reduction table, and provide the rules of managing alcohol sweetness.

How to use the alcohol dilution calculator?

There are many ways to use the alcohol percentage calculator for spirits - we'll show you the most popular way.

  1. You need to choose what kind of strong alcohol are you going to use?

    • Strongest consumable alcohol, rectified spirit, has an alcohol content of 95% – it is often used for making tinctures.

    • Standard vodka has an alcohol content of 40%.

  2. Are you going to mix it with water or with a weaker spirit? 🚰

    • Enter 0% for water.

    • Remember, it has to have a lower percentage than the strong alcohol!

  3. Choose your target alcohol content.

    • It also has to be lower than the strong alcohol percentage.
  1. Enter the amount of strong alcohol you want to use.

  2. Your results are here! – you'll get the amount of water/weak alcohol you need to obtain your target alcohol concentration.

If you click the advanced mode button, you'll also get the amount of alcohol lost due to contraction.

Did you enjoy using this alcohol dilution calculator? Then you might like to try our other alcohol-related tools:

How to dilute alcohol?

Sometimes you may need to work out an alcohol dilution, but heaven forbid you can't get a hold of this distilling calculator! We know that will never happen, but if you want to calculate alcohol dilution with your own knowledge – follow the guide below!

  1. The easiest way to calculate all the data needed is to use the cross method.
Cross method for alcohol dilution calculator.


  • A – Concentration of alcohol in the stronger spirit, given as a %;
  • B – Concentration of the weaker spirit or water, given as a %;
  • C – Target concentration of our final solution;
  • D = C - B is the parts of strong alcohol that we need to add; and
  • E = A - C is the parts of weaker spirit/water that we need to add.
  1. Enter all your data into the cross scheme and calculate D and E. (It's easy to remember – you always have to subtract the lower value on the cross from the upper value.)

  2. The result is a ratio of the strong alcohol needed and the weaker spirit/water needed.

    Let's say that D = 65 and E = 30, and we have 100 ml of strong alcohol. That means that for every 65 parts of stronger alcohol, we'll need to add 30 parts of weaker alcohol/water.

    We need to use the proportions:

    D --- Amount of strong alcohol

    E --- Amount of water needed

    Let's transform it:

    Amount of water needed = (E × Amount of strong alcohol)/ D

    Amount of water needed = (30 × 100 ml)/ 65

    Amount of water needed = 46.15 ml

  3. That's that - we got it!

But how to dilute 91 isopropyl alcohol to 70%?

Simply use the 91% isopropyl alcohol as the stronger spirit and use water as a weaker spirit. Your target value is 70%.

Want to learn more? You may also try our tool for general solution dilution. ⚗️

Sweetness of the homemade alcohol

Our dilution calculator in percent won't tell you how sweet your alcohol should be - that decision is all yours. However, we decided to gather all the information to make it as easy as possible.

What can we use to sweeten up our alcohol?

  • We can use either syrup, honey, or regular sugar of any kind. Honey is 30% less sweet than sugar.

What is the volume of added sugar?

  • 100 g of sugar takes 60 ml of volume
  • 100 g of honey takes 75 ml of volume

What are the ranges of sweetness for alcohol?

The presented ranges are characteristic of tinctures

  • Dry, 5 g of sugar in 1 L of solution;
  • Semidry, 51-120 g in 1 L of solution;
  • Semisweet, 121-220 g in 1 L of solution;
  • Sweet, 221-330 g in 1 L of solution; and
  • Liqueur and crème, >331 g in 1 L of solution.

Alcohol contraction

Bad news - when you mix alcohol solutions, their volume shrinks. This is due to some of the alcohol molecules present being able to fit neatly between the water molecules. This process is called alcohol contraction. Luckily, the amount of contraction is not that large.

How much spirit are we going to lose while mixing our alcohol?

Find the estimated amount in the table below:

Total amount of mixture

Alcohol concentration (in %)

Amount lost (in mL)

1 liter



1 liter



1 liter



1 liter



1 liter



1 liter



1 liter



1 liter



1 liter



1 liter



Łucja Zaborowska, MD, PhD candidate
Alcohol content
Strong alcohol
Water / weak alcohol
Alcohol volume
Strong alcohol
US fl oz
Water / weak alcohol
US fl oz
Final volume
US fl oz
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