Ratio
The ratio for artificial hummingbird nectar is four-parts water to one-part sugar. For example, you would use 4 cups of hot tap water and 1 cup white sugar to make acceptable nectar.
Directions
Mix the two ingredients together in a glass or stainless steel saucepan. Place a cover on the pan and set it on a burner over medium-high heat. Stir the mixture until the sugar has dissolved. Bring the liquid to a rolling boil then remove it from the burner. Allow the mixture to cool before placing it a clean feeder.
Considerations
The birds require real sugar. Do not use a sugar substitute because anything other than sucrose won't help the bird and could potentially harm it.