Specific Gravity Converter

Convert between SG, °Brix, °Plato, °Baumé, and API gravity

Conversion Settings
1 10
Current: 3
Conversion Result
°Brix
Equivalent: - kg/m³
Conversion Formula:
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Recent Conversions
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Unit Information

Specific Gravity is a dimensionless unit defined as the ratio of the density of a substance to the density of water at a specified temperature (usually 4°C where water has its maximum density).

Formula: SG = ρsubstance / ρwater

Uses: Brewing, winemaking, chemistry, petroleum industry, geology.

Degrees Brix (°Brix) is a measure of the sugar content in an aqueous solution. One degree Brix is 1 gram of sucrose in 100 grams of solution.

Formula (approximate): °Brix = 261.3 × (1 - 1/SG)

Uses: Food industry, winemaking, fruit juice production.

Degrees Plato (°P) is a measure of the concentration of dissolved solids in a liquid, mainly used in brewing. It's very similar to Brix but with slightly different conversion formulas.

Formula (approximate): °P = -616.868 + 1111.14 × SG - 630.272 × SG² + 135.997 × SG³

Uses: Brewing industry (beer wort measurement).

Understanding Specific Gravity Conversions

What This Converter Does

This tool instantly converts between six different density measurement scales used across various industries. It transforms:

  • Specific Gravity (SG) - Pure ratio relative to water
  • °Brix - Sugar concentration in liquids
  • °Plato - Dissolved solids in brewing
  • °Baumé (Light & Heavy) - Industrial solution density
  • API Gravity - Petroleum industry standard

All conversions use industry-standard formulas with SG as the common intermediary.

When to Use This Conversion

  • Home Brewing: Convert hydrometer readings between SG and Plato. For precise calculations, you might also need our weight-to-volume conversions for ingredients.
  • Winemaking: Translate Brix to specific gravity for alcohol potential
  • Chemistry Labs: Convert between density measurement systems. If you're working with solutions, our concentration converter can be a helpful companion tool.
  • Petroleum Industry: Switch between API gravity and specific gravity
  • Food Production: Standardize syrup and juice concentration measurements
  • Academic Studies: Compare different density scales in experiments. For broader physics applications, consider our online density converter.

How Conversion Works

The tool uses a two-step process:

  1. Converts your input unit to Specific Gravity (the common reference)
  2. Converts that SG value to your desired output unit

This ensures mathematical consistency across all conversions. Think of SG as a universal translator between different density "languages."

Note: Formulas are industry-standard approximations valid for typical measurement ranges.

Input & Result Guidance

Using the Input Field

  • Enter numbers with or without decimals (1.050 or 12.5)
  • Use negative values for API gravity (typical range: -50 to 100)
  • For brewing: Typical SG range is 1.030-1.100
  • For Baumé: Positive values typically 0-70 degrees
  • Click the X button to quickly clear input

Interpreting Results

  • SG values: Always above 1.0 for liquids denser than water
  • Brix/Plato: Higher values mean more sugar/solids
  • API gravity: Higher values mean lighter petroleum products
  • Density equivalent: Shows mass per cubic meter for reference
  • Use decimal places slider for precision matching your instrument

Accuracy & Limitations

  • Temperature: Conversions assume standard temperature conditions (usually 20°C/68°F)
  • Range validity: Formulas optimized for common industrial ranges
  • Rounding: Adjust decimal places to match your measurement precision
  • Extreme values: Very high or low values may have reduced accuracy
  • For critical applications: Always verify with calibrated instruments

Last formula verification: November 2025

Common Mistakes to Avoid

  • Confusing Baumé Light vs Heavy scales (select correct option)
  • Assuming Brix and Plato are identical (they differ by ~0.1-0.5%)
  • Forgetting temperature affects actual density measurements
  • Using too many decimal places beyond instrument capability
  • Mixing up API gravity sign (can be negative for very dense oils)
  • Not using Brewing Mode for beer/wort specific conversions

Practical Examples

Beer Brewing

Original Gravity: 1.050 SG = ~12.4°P
Final Gravity: 1.010 SG = ~2.6°P
Alcohol by volume calculation uses this difference. You can then convert the ABV using our calorie converter for nutritional info.

Wine Must

Grape juice: 23°Brix = ~1.096 SG
Potential alcohol: ~13.5%
Each 1°Brix ≈ 0.55% potential alcohol. Use our specific gravity converter for precise must measurements.

Crude Oil

Light crude: 35°API = 0.8498 SG
Heavy crude: 20°API = 0.9340 SG
Higher API = lighter oil = more valuable. You can calculate the weight of a barrel with our weight converter.

For Students & Learners

  • Use "Show Formula" to understand mathematical relationships
  • Experiment with extreme values to see scale behaviors
  • Compare Brix vs Plato to understand approximation differences
  • Note that SG is unitless while others are "degrees"
  • Observe how density (kg/m³) changes with different scales
  • Use history feature to track your experimental conversions

Learning tip: SG is the fundamental reference—all other scales derive from it. For related physics concepts, try our stress unit converter or strain converter.

Professional Notes

  • Brewing: Enable Brewing Mode for Plato-focused conversions
  • Quality Control: Use consistent decimal places for reporting
  • Documentation: Copy results directly to reports with one click
  • Calibration: This tool supplements but doesn't replace instruments
  • Batch Processing: History stores last 5 conversions for reference
  • Standard Reference: Formulas based on ASBC, OIML, and ASTM standards

Accessibility & Compatibility

Accessibility Features

  • Full keyboard navigation support (Tab, Enter, Arrow keys)
  • Screen reader compatible labels and descriptions
  • High contrast modes via Dark/Light theme toggle
  • Clear visual focus indicators for interactive elements
  • Adjustable text size through browser zoom
  • No dependency on color alone for information

Device Compatibility

  • Mobile: Fully responsive on smartphones and tablets
  • Tablet: Optimized touch targets and spacing
  • Desktop: Efficient keyboard and mouse interaction
  • Browser: Works on Chrome, Firefox, Safari, Edge (latest versions)
  • Offline: Partial functionality after initial load
  • Print: Clean printing of conversion results

Frequently Asked Questions

Both measure dissolved solids, but use different conversion formulas. Brix is for sucrose solutions, Plato for brewing wort. They differ by 0.1-0.5% in most ranges. Brewers use Plato, winemakers use Brix.

The Baumé scale has separate versions for liquids heavier than water (heavy scale, °BéH) and lighter than water (light scale, °BéL). They use different formulas to maintain linearity across the density range.

Conversions use industry-standard polynomial approximations. For typical brewing/industrial ranges (SG 0.9-1.2), accuracy is within ±0.1%. For extreme values or scientific applications, consult specific density tables.

Yes, significantly. All conversions assume standard temperature conditions (usually 20°C/68°F). Actual density measurements must be temperature-corrected before conversion. This tool handles scale conversions only.

This tool is suitable for calculations, estimations, and educational purposes. For formal reporting, critical quality control, or scientific publication, verify with primary references and calibrated instruments.

Version Information

Current Version: 2.1 (November 2025)

  • Updated polynomial approximations for wider validity ranges
  • Enhanced mobile responsiveness and touch interactions
  • Added equivalent density display in kg/m³
  • Improved formula documentation and accuracy notes
  • Extended conversion history to 5 entries
  • Optimized for all modern browsers and devices