How to Estimate Carpet in a Building

Estimating the amount of carpet needed for a whole building will require a series of calculations and additions. Carpet is sold by square yards, but rooms are typically measured in square feet. The widest carpets are 12 feet or 15 feet wide. For shorter or wider spaces, you will need to cut and patch pieces together along the same weave direction. To factor in carpeting stairs successfully, some extra measurements will be helpful to get the most accurate estimate.

Difficulty: Moderate

Instructions

Things You'll Need:

• Tape measure
• Building floor plan/blueprints
• Calculator

1. Review the building floor plans and architectural drawings. This is an easy way to initially estimate the floor space you are covering. Identify which of the rooms, hallways and stairs will be carpeted or plain floor.

2. Calculate the square footage of each floor by multiplying length and width of rooms and adding those totals together or by using the floor plan totals. Measure any offset corners or alcoves as a separate "small room" to add to the total. Subtract any areas that will remain uncarpeted.

3. Measure staircases that will be carpeted by finding the stair depth front to back and height multiplied by the number of stairs for the length. Find the width of the steps by measuring side-to-side. In essence this becomes your "room dimension" estimate, knowing that stairs will require a little extra fussing. You should add up to 3 inches extra per stair to the length if a carpet pad is going underneath the carpet.

4. Add the total square footages of the rooms on each floor. Keep a separate total for staircases. Add the floor and stair totals all together for the whole building total size in square feet. As carpet is measured in yards, and there are 9 feet in each square yard, take your total building square footage and divide by 9 for your total carpet square yardage.

5. Take the floor plans and your estimates with you to the carpet store when you go to purchase your carpet. The installers can affirm your calculations or recommend adjustments for oddly shaped areas or overall totals.

Tips & Warnings

• Remember that in estimating carpet needs it is better to aim for having extra inches in coverage rather than measurements that are too tight to complete the project. Room sizes average 10 feet wide (10 x 10 = 100 sqare feet), where carpet is measured in 12-foot widths, typically. To minimize unnecessary seaming and cutting throughout the room, buy carpet at the length of your room (12 feet by 10 feet = 120 square feet) and discard the excess.
• When double-checking your room count and floor totals against the blueprints, any major discrepancy should be recalculated.

References

• Planning Your Carpet Size

Resources

• How to Install Carpet on Stairs
• Bankrate Calculators