To accurately measure planting pots, start by determining the top diameter, which is the widest point at the rim. Use a tape measure or ruler to find this measurement. Next, measure the depth, or height, of the pot from the rim to the bottom. Finally, calculate the volume or capacity of the pot to ensure it has sufficient space for the plant’s root system. Use the formula: Volume = πr²h, where ‘r’ is the top radius and ‘h’ is the height. Convert the units to gallons or liters if necessary.