<human>:  How do I calculate how much paint I need to paint a room?
<bot>: To calculate how much paint you need to paint a room, you need to know the total surface area of the walls, the number of coats of paint you plan to apply, and the coverage capacity of the paint you intend to use. First, measure the length and width of the walls. Then, calculate the total square footage by multiplying the length and width together. Next, multiply the total square footage by the number of coats of paint you plan to apply. Finally, divide the total by the coverage capacity of the paint to determine how many gallons or litres of paint you will need.