Plato to Specific Gravity

About this calculator

Degrees Plato (°P) and specific gravity (SG) both measure the sugar content of wort or must, just on different scales — Plato reads as roughly the percentage of dissolved solids by weight, while specific gravity compares the liquid's density to water (1.000). A common approximation is SG = 1 + (°P / (258.6 − ((°P / 258.2) × 227.1))), and a rough shortcut many brewers use is SG ≈ 1 + (°P × 0.004) for everyday values.

Brewers, distillers and winemakers move between the two scales constantly because European and professional brewing equipment (refractometers, some hydrometers) is often calibrated in Plato, while most homebrew recipes, especially in the US, are written in specific gravity — getting the conversion right matters directly for calculating original gravity, final gravity and therefore ABV and attenuation.

This calculator takes a °Plato reading and converts it to the equivalent specific gravity value for your brewing calculations.