You can use these calculators to calculate Brix, chaptalization, and sulfite for your wine.

Brix Conversion Calculator | Brewer's Friend
Converts Brix to Specific Gravity and Specific Gravity to Brix.

Chaptalization Calculator | Brewer's Friend
Chaptalization calculator finds how much sugar to add to your must to hit the desired Brix.

WineMaker Magazine - Sulfite Calculator
The Sulfite Calculator is a simple yet very useful tool to quickly calculate the amount of sulfite needed to adequately protect a wine.