The calculator will work out your hydration level based on the information you give about yourself and your daily drinking habits. See the methodology.
Most plants in the ground do fine with a couple of good 15-minute soaks each week. On hot weeks, just check the soil between those waterings to ensure it hasn'.
The Eatwell Guide recommends that people should aim to drink 6 to 8 cups or glasses of fluid a day. Water, lower-fat milk and sugar-free drinks, including tea.
Women should have about 2 litres (8 cups) of fluids a day, and men about 2.6 litres (10 cups). People who are pregnant or breastfeeding need more fluid each day.