Ethanol Dilution Calculator

Diluting high-strength alcohol — such as lab-grade ethanol or homemade spirits — to a lower percentage requires precise water additions to hit your target concentration. Enter your Initial Alcohol Concentration, Initial Volume, and Target Alcohol Concentration into the Ethanol Dilution Calculator, then select your preferred volume unit to get the exact water to add, along with the final volume, dilution ratio, and pure alcohol volume.

%

Current alcohol percentage by volume

mL

Volume of your starting alcohol solution

%

Desired final alcohol percentage

Results

Water to Add

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Final Volume

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Dilution Ratio

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Pure Alcohol Volume

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Frequently Asked Questions

How do you calculate alcohol dilution?

Use the formula: Water needed = (Initial volume × Initial concentration / Target concentration) - Initial volume. This ensures the final mixture has your desired alcohol percentage.

Can you dilute alcohol with water?

Yes, you can dilute alcohol with distilled water. Always use distilled water to avoid introducing impurities that could affect taste or clarity of your final product.

How do you dilute 95% alcohol to 40%?

To dilute 95% alcohol to 40%, you need to add approximately 1.375 parts water for every 1 part of 95% alcohol. For example, 1000mL of 95% alcohol requires 1375mL of water.

Does the order of mixing matter when diluting alcohol?

Yes, always add water to alcohol slowly while stirring, never add alcohol to water. This prevents heat generation and ensures proper mixing without creating hot spots.

What is alcohol contraction and should I account for it?

Alcohol contraction occurs when alcohol and water mix, resulting in a slightly smaller final volume than expected. For precise work, the contraction is typically 2-3% and should be considered.

Can I use this calculator for isopropyl alcohol dilution?

Yes, this calculator works for any alcohol type including isopropyl alcohol. The dilution principles are the same regardless of the alcohol type.

How accurate are dilution calculations?

Dilution calculations are very accurate when using precise measurements. Use a graduated cylinder or scale for best results, and always measure at room temperature for consistency.

What's the minimum concentration I can achieve?

Theoretically, you can dilute to any concentration above 0%. However, very low concentrations require large amounts of water and may not be practical for most applications.