A suspended, or dropped, ceiling is a full ceiling that is built beneath the actual ceiling of a building. Many office buildings have suspended ceilings, for example, and place heating and air-conditioning ductwork in the space between the two ceilings. Measure a suspended type of ceiling as you would an actual ceiling, but also measure between the two ceilings if you need to place ductwork or electrical elements there.
Instructions
1. Measure the length of the suspended ceiling. Place a tape measure, yardstick, meter stick or other type of measuring device at one end of the ceiling and measure across to the other side.
2. Measure the width of your suspended ceiling. Place your measuring instrument at the other end of your ceiling and measure across to the other side. You could also measure the ceiling by measuring the walls that connect to it.
3. Find the distance between the suspended ceiling and the actual ceiling above it. This will require you to remove one of the ceiling tiles and may require the use of a ladder. Typically, this distance is about 1 foot, though it could be more or less depending on the type of building (for example, a home versus an office building or retail space). You may need to know this information if you're planning to have ductwork installed.
4. Multiply the length by the width of your suspended ceiling to find its square footage. This is useful if you are planning to replace tiles with those of a different size. Estimate how many ceiling tiles you will need (if your tiles aren't 1 square foot in size) by dividing the width of your ceiling by the width of the tiles. Next, divide the length of your ceiling by the length of the tiles. This will give you an indication of how many rows and columns of tiles you would need to purchase. Tiles placed near the point where your ceiling meets the wall likely will have to be cut to fit. You may also need square footage information if you're painting the ceiling and need to calculate how much paint to buy.
5. Find the square footage of a suspended ceiling that is not rectangular by diving it into smaller shapes and calculating the square footage of those shapes. For example, if your room (and by association, your ceiling) is "L" shaped, you can break that shape down into two rectangles. Measure the length and width of each rectangular portion of the ceiling and multiply those dimensions to find the square footage. Add the square footage calculations for each section together to find the total