ABV Calculator (No Initial Gravity)

About This Calculator

Curious about the alcohol content of your wine but don’t have the original gravity reading? Our ABV Calculator lets you accurately estimate alcohol by volume using only your wine’s Brix (B) and Specific Gravity (S).

The calculation is based on the proven formula:

ABV = 1.646 × B - 2.703 × (145 - 145/S) - 1.794

Here’s what it means and how to get the numbers:

  • Brix (B) measures the sugar content of your wine and is usually obtained using a refractometer, a simple handheld tool that quickly reads sugar levels in liquid.

  • Specific Gravity (S) reflects the density of your wine compared to water and is measured with a hydrometer, a floating device that gives an accurate reading of liquid density.

  • By entering these values into the formula, you get a reliable estimate of alcohol content, even without knowing your starting gravity.

This tool is perfect for home brewers, winemakers, or hobbyists who want insight into their batches. Knowing the ABV is essential for understanding the strength, flavor profile, and fermentation progress of your wine.

All calculations happen locally in your browser, so your data remains private and secure. In addition to providing a reliable ABV estimate, we offer practical tips for interpreting results, making recipe adjustments, and optimizing fermentation for consistent outcomes.

By using this calculator, you’ll gain confidence in tracking your wine batches, experimenting with new recipes, and achieving the perfect balance between sweetness, alcohol content, and flavor. Whether you’re producing small batches for fun or larger batches for sharing, this tool helps ensure every bottle meets your desired standards.

Use this calculator to:

  • Estimate ABV without gravity readings

  • Track fermentation outcomes

  • Compare batches or recipes

  • Improve consistency in winemaking

Enter Your Readings

°Bx
SG
Formula:
ABV = 1.646 × B - 2.703 × (145 - 145/S) - 1.794
Where B = Brix, S = Specific Gravity

Take readings after fermentation is complete and after racking, but before back sweetening for accurate results.

Calculated ABV

Alcohol By Volume

0.18%

Typical Values

Finished Dry Wine:
Specific Gravity: 0.990-0.998
Brix: Close to 0°

Sweet Wine:
Higher SG and Brix values indicate residual sugar

This calculator provides an estimate. For laboratory-grade precision, professional testing equipment is required.

Frequently Asked Questions

When should I use this calculator?

Why do I need both a refractometer and a hydrometer reading

I took an initial gravity reading before adding yeast. Can I still use this calculator?

Why is it important to calculate ABV before back sweetening?

Can I use this for beer or cider?

Frequently Asked Questions

When should I use this calculator?

Why do I need both a refractometer and a hydrometer reading

I took an initial gravity reading before adding yeast. Can I still use this calculator?

Why is it important to calculate ABV before back sweetening?

Can I use this for beer or cider?

Frequently Asked Questions

When should I use this calculator?

Why do I need both a refractometer and a hydrometer reading

I took an initial gravity reading before adding yeast. Can I still use this calculator?

Why is it important to calculate ABV before back sweetening?

Can I use this for beer or cider?

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