Brix can be
approximately converted to specific gravity (SG) by a simple equation: SG = 1
+(0.004 x Brix)
Most people just remember the multiply by four rule. Take the Brix reading,
multiply by 4 and this will give you specific gravity in gravity points. For
example, if you read 11 Brix, multiplying that by 4 yields 44, which corresponds
to a specific gravity of 1.044.
A slightly more accurate conversion formula is:
SG = 1.000019 + [0.003865613(Brix) + 0.00001296425(Brix) +
0.00000005701128(Brix)] Using this formula, a Brix reading of 11 yields a
specific gravity of 1.043.