3 liters of water is equivalent to 3 standard 1-liter bottles of water. If you are using smaller bottles, for example 500 ml (0.5 liters) bottles, then 3 liters would be 6 bottles of 500 ml each. So the number of bottles depends on the bottle size:

• For 1-liter bottles: 3 bottles
• For 500 ml bottles: 6 bottles
• For 330 ml bottles (typical small bottles): about 9 bottles (3 ÷ 0.33 ≈ 9)