Refractometer / Brix / SG / Plato Conversion Calculatorv1.0.0

This calculator converts between Degrees Brix, Specific Gravity (SG), and Degrees Plato, with built-in wort correction factor support and alcohol-adjusted readings for post-fermentation measurements. It operates in three modes to cover every stage of the brewing process.

• Select a Mode from the dropdown at the top. Pre-Fermentation mode corrects a raw refractometer Brix WRI reading into actual Brix, Plato, and Specific Gravity values. Post-Fermentation mode takes both OG and FG refractometer readings and corrects the FG reading for alcohol presence, providing corrected gravity values and estimated ABV. Direct Conversion mode converts any single value between Brix, Plato, and SG without wort correction.
• In Pre-Fermentation mode, enter your refractometer reading in the OG Brix WRI Reading field. The calculator divides by the wort correction factor (default 1.04) to produce corrected Brix and Plato values, then converts to Specific Gravity using the ASBC polynomial.
• In Post-Fermentation mode, enter the OG Brix WRI Reading and the FG Brix WRI Reading. The calculator applies the Novotny correction formula from Zymurgy (July/August 2017) to account for alcohol refraction error and outputs corrected OG, corrected FG, ABV, and apparent attenuation.
• In Direct Conversion mode, enter a value and select the input unit. The calculator instantly shows the equivalent in all three scales.
• Open Settings to adjust the Wort Correction Factor (standard is 1.04), change the number of Decimal Places for SG output, or enable Show step-by-step formulas to see the mathematical derivations.
• All numeric fields accept decimals (12.5), fractions (25/2), and mixed numbers (12 1/2). Results update automatically after a short pause, or press the Convert button manually.
• Press Reset to clear all values and restore defaults. All inputs and settings persist between visits using browser storage.

Convert refractometer readings to brewer-friendly gravity units across the full brewing workflow, from mash efficiency checks through final gravity measurement and ABV estimation.

• Brew Day Efficiency: Take a quick refractometer reading of your first runnings or pre-boil wort and convert Brix WRI to Specific Gravity to calculate mash or brewhouse efficiency on the fly without cooling a full hydrometer sample.
• Fermentation Monitoring: Track fermentation progress by entering both OG and current refractometer readings in Post-Fermentation mode. The alcohol correction formula provides an accurate current gravity estimate without pulling a large sample from the fermenter.
• Final Gravity and ABV: Determine final ABV and apparent attenuation at the end of fermentation using only a refractometer. Compare results against hydrometer readings to validate your wort correction factor.
• Winemaking: Convert Brix readings from grape must to Specific Gravity for recipe formulation and potential alcohol estimation. Adjust the wort correction factor to match your refractometer and must composition.
• Recipe Development: Convert target gravity values between Brix, Plato, and SG when following recipes from different brewing traditions. European recipes often specify Plato while American home brew recipes use SG.
• Refractometer Calibration: Compare corrected refractometer readings against hydrometer measurements across multiple worts to determine your instrument's specific wort correction factor for improved accuracy.
• Professional Brewing: Convert between Degrees Plato (used in continental European and professional brewing) and Specific Gravity (common in American and British home brewing) for communication across brewing communities and documentation standards.
• Education: Visualize the relationship between sugar concentration scales using Direct Conversion mode and the step-by-step formula display to understand how Brix, Plato, and SG relate mathematically.