Cocktail syrup calculator

Sugar & water by weight, with proper solution density

Ratio (water : sugar, by weight)
Final syrup volume
IngredientWeight
Sugar g
Water g
Total mass g
Brix %
Density (20 °C) g/mL

How the math works

Ratios are expressed by weight, not volume — sugar's bulk density depends on grind and packing, so volumetric measurement is unreliable. With ratio w : s, the mass fraction of sugar (Brix) is B = s / (w + s). So 1:1 → 50% Brix, 1:2 → 66.67% Brix.

A sucrose solution's density at 20 °C is a known function of Brix — not a linear mix of the components, because dissolving sugar contracts the volume slightly. This page interpolates the standard NIST/ICUMSA sucrose density table (Bates 1942) at 5% intervals.

From your target volume V and the looked-up density ρ(B): total mass M = V · ρ(B), then sugar = M · B and water = M · (1 − B).

Note: weigh at room temp before heating. Hot syrup has lower density, so a hot 500 mL pour is less than 500 mL once cooled. Measure final volume cold if it matters.