Making a standard curing brine calls for weighing the meat + water to calculate the amount of salt and sugar. Then taking the weights of the meat + water + salt + sugar, and using that total weight to calculate the amount of Cure #1 which is always 0.25% *. For corned beef you add from 1 tablespoon to 3 tablespoons of pickling spices. Some people will add garlic, more mustard seeds peppercorns etc., for a more personal touch.
* some calculators do not take into account the weight of the salt and sugar, they only use meat + water. Other calculators will use meat + water + salt, but don't even have a place for sugar.
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An easier method is to use Pop's Curing Brine, which is a universal curing brine with a low concentration of Cure #1. It uses longer curing times and the benefit is a less 'tinny' flavor and more tender end product.
1 gallon water
1/3 to 1/2 cup of canning salt*
1 cup of white sugar**
1 cup of brown sugar**
1 heaping tablespoon of Cure #1, which is 1 ounce or 20 grams.
1 to 3 tablespoons of pickling spice or other signature spices mentioned above.
This is mixed into room temperature water. If you warm your water to dissolve the salt and sugar don't add the Cure #1 until the brine has cooled down to room temperature. Brine time for corned beef is 10 to 20 days, and calls for injecting some of the brine if the thickness is >2".
*Pops original recipe called for up to 1 cup of salt, but suggested 1/2 cup as a starting point and then adjusted to taste for future projects. He recommended 1/3 cup if you want a lo-salt product
**For my personal tastes, and because I mix lower salt brines and cures this is a little too sweet for me, so I reduce the sugar. On beef I only use white sugar.
. I see the recipe in the “Great sausage recipes and meat curing” book but it calls for an injection as well. 
