# How to Calculate Roof Tile

Once your roof begins to leak, you know it is time to replace the tiles on your roof.
Roof tiles are very durable but will need to be replaced over time.
You can also examine the tiles from the outside of your home. Any time you begin to see curled shingles or cracked tile it is time to perform some repairs. Save money by performing the repairs yourself. To avoid waste, calculate the number of square feet on your roof in order to know how many roof tiles to purchase. You will need to climb on your roof and make a sketch in order to come up with the most accurate number.

### Step 1

Draw a sketch of your roof as if you were looking at it from above. Walk around your home and take note of all areas that stick out alone, such as above doors and windows. Make note of changes in pitch or height of the roof.

### Step 2

Divide each section up in squares and calculate the square footage of each section. Multiply the length times the height. Carefully use a ladder to climb up to the roof. Measure the length along the edge of the roof and measure the height to the very top of each section. Lay the tape measure on the roof and take a measurement up to the top of the roof and down the backside. Multiply the two numbers together to get the number of square feet.

### Step 3

Calculate each section separately and add the numbers together to get the total square footage.

### Step 4

Divide the total number of square feet by 100. This will give you the number of tiles that you need to retile your entire roof.

### Step 5

Add 10 percent to the total number to allow for waste, starter and extra shingles and caps. For example, if you need 500 total tiles to retile your roof you would add an extra 50 tiles to ensure you have enough to complete the job.

• Ruler
• Calculator
• Tape measure