Everyone knows that you need to drink plenty of water each day to stay hydrated, but a big question is how much you really need to drink in order to accomplish that. Our bodies are about 60 percent water, scientists say, and the H2O is certainly the most important ingredient in our lives, but it’s not so clear exactly how much we need to take in on a daily basis to survive and thrive.

Common knowledge is to drink eight 8-ounce glasses of water per day, or about two liters, but scientists say that’s not necessary. Many studies suggest that we don’t need nearly this much water, and scientists have yet to come to a consensus on what the ideal amount of water to drink is.

The reality is, our bodies don’t function off drinking a certain amount of water. That’s for a variety of reasons, one of which is that much of the water we get comes through our food. If you eat plenty of raw fruits and vegetables, you probably get a lot of water through your food, but if you don’t you may need to drink more water. Also, we get water from non-alcoholic drinks, so that needs to be factored in as well.

Then there’s how much you exercise. If you exercise a lot, you’ll lose a lot more water in sweating, but if you don’t exercise at all you retain a lot more water. And if you live in a hot climate you’re going to sweat a lot more than if you live in cold areas.

Scientists say the best thing to do is just let thirst guide you. Our bodies are very good at signaling to our brains that it is time to get a glass of water, so just listen to it.