Honey

12 pounds of honey = 1 gallon

Honey weighs 0.80 pounds per cup

1 lb. honey = 1.25 cups

Each pound of honey also adds about 35 gravity points, bringing the must original gravity from that of water, 1.000, to 1.035. This means each alcohol percentage point is approximately 7 gravity points

3 pounds of honey per gallon of must equals potential alcohol by volume of about 15%. You will then have an original gravity of about 1.105 (3 * 35 = 105 gravity points, for an OG of 1.105).

The final volume should be one gallon. It assumes 1 pound of honey per 1 gallon must volume (final volume). For 3 lbs honey per gallon (roughly one quart), you would add 3 quarts water to the honey volume for one full gallon.

To backsweeten a mead, determine the final gravity you want your mead to be, then depending upon your current gravity, add the requisite amount of honey (at 35 gravity points per pound).

If the FG of a 1 gallon batch is 1.000 and you wanted to raise it to 1.020, adding a full pound would make the FG 1.035, too high. A half pound would make it 1.018, which is close, while 3/4 of a pound (1 cup) would make it 1.026 a little over. 2/3 of a pound would get you to 1.023.

Now if you have more than 1 gallon, just multiply that by your number of gallons. So if you have a 3 gallon batch, and you went with the 3/4 lb, you would then multiply it by 3, or 2.25 lbs. Since that would have put you on a slightly sweeter side, you could probably reduce it to 2 lbs and be on target (that would also be equivalent to the 2/3 lb of honey determination).

Or you can use this calculator:

http://mcarterbrown.com/mead/mead2.html

OR my own calculator here (better):

https://docs.google.com/spreadsheets/d/1_Z9eJmxWY1UyYx2L_-zYrRrB0SP50adzYw_LbWZt-1c/edit#gid=0

Sugar additions:

1 c (packed) light brown sugar raises gravity 0.020