I had always wanted an "artificial" sweetener that worked for me, but I have always been extremely sensitive to them. Not that they give me headaches or anything like that, I just find them vile. The aftertaste especially was just nasty to me.
Then one day I was offered a water with a couple of drops of flavoring. It was like drinking lemonade. Sugar sweetened lemonade! Well, it obviously wasn't sugar sweetened, because that would have taken more than a couple of drops. I'm a naturally curious food nerd, so I read the label of the drops. The drops were the brand name Dasani, and the sweeteners were sucralose and acesulfame potassium (Ace K). I had never heard of Ace K, and I already knew I didn't like sucralose (alone). This was not boding well, but I was intrigued. So, I used every bit of Google-fu that I had (and a lot that I didn't) to learn this:
Pure sucralose is about 600 times as sweet as sugar (by weight). Ace K is about 200 times as sweet as sugar (also by weight). Combine them, and they become "sweeter than the sum of their parts". This is not within the scope of your question, but I will tell you this too (also borne out by my lengthy research): Ace K works beautifully to wipeout the aftertaste that other artificial sweeteners tend to have, particularly sucralose and aspartame (nutrasweet). So, by combining Ace K and another sweetener (I recommend sucralose), you get two benefits. Number one, it takes less of each to sweeten whatever it is you're trying to sweeten, and number two, you knockout the aftertaste of the sweeteners.
So, to get started, you need a gram scale (they're not just for chemists and drug dealers):
This one is mine, $10
You also need pure sucralose, 50 grams lasted me over two years, $19, 100 grams is only $3 more
Ace K, the smallest amount on Amazon might last a lifetime, 1 pound, $13
Use the gram scale and mix the sweeteners 50/50 by weight. Pull your shirt over your mouth and nose or wear a mask to mix them, otherwise you will taste sweet for days. A scant 1/8 teaspoon of the combo will sweeten an entire double-strength, 12 cup pot of coffee (which I mix with milk to create iced coffee). You can also bake with it. It's amazing stuff. To me (artificial sweetener phobic), it's indistinguishable from sugar.
EDIT: Yoplait has recently started advertising that their light yogurt is aspartame free. What are they using instead? Ace K and sucralose.