The recommended coffee-to-water ratio for making iced coffee is usually 1:15 to 1:17. However, you can adjust it based on your preference for a stronger or milder flavor.  The coffee-to-water ratio refers to the amount of coffee grounds to use in proportion to the amount of water when making iced coffee. For example, a ratio of 1:15 means using 1 part coffee grounds to 15 parts water. This ratio helps determine the strength and flavor of the iced coffee. By adjusting the ratio, you can control the intensity of the coffee flavor.