The easiest and very well-created ingredient combinations for different sausages are premade mixes.  I purchase mine from Butcher Packer (  Saves me from having lots of bulk ingredients on hand which can go stale, and they are relatively inexpensive and well-sealed.  Most call for a set amount of product, i.e. "Mix 25 lbs. of pork with..".  But!  what if you only want to use 3¼ lbs?  How do you know how much to use?
I use mostly commercial seasonings from Butcher Packer, they are very well prepared. But, the problem that arises is how much do you use if you're not making the full amount listed on the package?
For example, their Smoked Polish Sausage Seasoning lists instructions for making 25 lbs. of product:
25lbs pork butts/picnics
1 oz curing salt (DQ cure - 6.25% nitrite)
2 oz binder
3 lbs water
The weight of the seasoning packet is 11 oz.

Now, that's just fine if you're going to make 25lbs. of product. But, my meager resources (wife's a cancer survivor.. drains ya..!) only allow me to buy one or two butts at a time and many times I'm making Italian and Breakfast sausages as well as Polish, so I may only have 3 lbs. 5 oz.. of pork reserved for the Polish Sausage. How to I translate the ingredients from 25lbs. to 3lbs. 5oz. accurately so I get it right? Especially if you're dealing with 1 oz of something that is critical not to use too much (nitrite)?

Well, first you have to find out your proportional amount. So, divide the amount you're going to use (3lb. 5oz.) by the weight listed (25 lbs). But, you're dealing with pounds and ounces and that won't divide out. However, if you convert them to ounces, you can divide those:
at 16oz. per pound, 3lb. 5oz is 53oz. (48+5) and 25lb. is 400. 53 divided by 400 = .1325 or 13.25%. You're using 13.25% of the full amount, so therefore, you can use 13.25% of each ingredient to make it proportionally correct.
Now, however, it's hard to figure out what 13.25% of 11 oz. is. But, if you convert your ounces to grams, then it's easy as grams are based on 10's and are a much smaller measurement. If you print out a conversion chart from:
you can see that 11 oz. is 311.84 grams (make it 312). Multiply 312 by .1325 and you have 41.34 grams, or about 41 grams is close enough. So, you'd measure out on your scale set to grams 41 grams of seasoning.

1oz. of cure would be .1325 of 28.34 grams, or 3.75 grams of cure - measure out just 4 grams is as accurate as you can get.

2 oz. of binder would be 56.69 x .1325 or 7.51 grams, measure 8 grams.

3lbs. of water would be 3x16 or 48 oz., which is 1360.77 grams x .1325, or 180.30 g. - measure 180 grams.

Now, put a small container on your scale and set the tare to zero. Set the scale to grams, add water to 180 g. Add binder to 188 g (180+8), then add cure to 192 (188+4). You now have the proper proportion of ingredients to season 3lbs. 5 oz. of meat! And, you won't kill anyone by using too much nitrite!

Hope this is understandable; if not just ask and I'll try to further explain anything more.