All non-alcoholic drinks count towards your daily water intake, including hot drinks such as tea and coffee. Water, milk and fruit juices are the healthiest.
Source: Water and drinks @ NHS Choices
- What Counts as Water? Stay Hydrated and Healthy @ WebMD
Excerpt: Coffee and tea also count in your tally. Many used to believe that they were dehydrating, but that myth has been debunked. The diuretic effect does not offset hydration.