No answers are simple. If you’re talking about Equal-brand sweetener, you have to specify which version. Each packet of Equal equals (we don’t know how else to say it) the sweetness of 2 teaspoons of sugar. With Equal for Recipes, a distinct product, 1/4 teaspoon equals the sweetness of 2 teaspoons of sugar. Finally, Equal Spoonful measures spoon-for-spoon with sugar.
Now, you cannot substitute Equal willy-nilly in your recipes, even if you get the ratio right. Equal tends to break down and lose its sweetness in cooking. In addition, sugar accomplishes more in recipes than simply adding sweetness. It affects the texture, color, and bulk, among other things, and Equal does not react in the same way at all.
Merisant, the manufacturer, says that Equal works especially well in fruit pie fillings, but is a wash-out in cakes, cookies, and other pastries. It also suggests that you experiment with the amount of Equal in your recipes to get just the taste that suits you.
It's new Equal Sugar Lite, a mixture of sugar and aspartame, is meant to address all the baking problems inherent in the aspartame-only versions of Equal. The company says you substitute it in recipes on a one-to-one basis for sugar, and it "bakes, browns, and provides volume" as if you had used only sugar. The resulting dish will have half the calories and carbohydrates. Unfortunately we can't actually find it anywhere - even in the Equal store online....