Does Over Consumption of Water, Caffeine, and alcohol Kill You? Research Report.
This chart shows the amount of water, caffeine and alcohol that, consumed all at once, would kill a typical human. The figures are averages only — half the population would likely survive the doses shown above, while for others, a much lower dose might be fatal. The numbers are also estimates based on testing in animals, which means they are largely speculative. Still, they are useful for comparing the toxicities of chemicals in a broad way. If you were chugging cups of coffee, you’d die from the water before the caffeine. For more on the scientific difficulties and ethical problems involved in calculating lethal doses.
Source: Washington Post