For a 32oz Nalgene Bottle (the standard biggish one) of clean water, the Oral Rehydration Salt quantities are:

  • Slightly less than 1/2 teaspoon of Salt (0.43tsp. to be exact)

  • 7.5 teaspoons of Sugar

(Personal note: when you’ve made it correctly, it should taste like minusculey-sweet saliva)

Adapted from Rehydrate.org’s ORS Recipe based on 1 liter of water.

And the wikipedia entry on Oral Rehydration Salts (ORS)