Loan Carpet Estimator
Carpet is the one floor covering sold by the square yard and delivered on a roll — so the real questions are yards, roll length and seams. Two rooms, one waste allowance, straight answers.
Padding (underlay) covers the same area as the carpet — the estimator sizes both from the same number. Rooms wider than the roll need seams; the 10% allowance absorbs the extra width that seaming eats.
How it works
Add the room areas, apply the waste allowance, and divide by 9 — carpet is priced per square yard (9 sq ft). Roll length is the with-waste area divided by the roll width: carpet comes off a 12-ft roll, so a 198 sq ft order is a 16.5-ft cut. Padding is sold in rolls and bundles rated by square yards and simply matches the carpet area. The waste figure does real work in carpet: pile direction must run the same way in every piece, so offcuts cannot always rotate into another corner the way tile or flooring offcuts can.
Formula & worked example
Formula: Square yards = (room areas summed × (1 + waste)) ÷ 9. Padding matches the same square-yard figure. Roll length = area with waste ÷ roll width (12 ft standard), which is the cut length to ask the warehouse for.
Worked example: A 12 × 15 ft room: 180 sq ft, 198 with 10% waste — exactly 22.00 sq yd of carpet and padding, cut as 16.5 ft off a 12-ft roll. Add a 10 × 12 ft second room and the order becomes 45.47 sq yd.
When to use this
- Ordering carpet for a room or two and needing square yards, not square feet.
- Comparing retailer quotes — one in sq ft, one in sq yd — on equal footing.
- Budgeting padding with the carpet instead of as a checkout surprise.
- A landlord refreshing units between tenants, room by room.
How to use it, step by step
- Measure each room's length and width (into closets the carpet will enter).
- Enter a second room if it shares the same carpet and dye lot.
- Keep waste at 10% for plain carpet, 15–20% for patterns.
- Note the roll length at your roll width — that is the warehouse cut to request.
- Confirm the installer's measurement before the order is final.
What the inputs mean
| Input | What it is | Typical values |
|---|---|---|
| Room dimensions | Length × width of each carpeted room | Bedrooms 10–14 ft, living 12–20 ft |
| Waste % | Seaming and pile-direction allowance | 10% plain, 15–20% patterned |
| Roll width | Width of the carpet roll being cut | 12 ft standard |
Another worked example
Two bedrooms on one dye lot: 14 × 18 ft (252 sq ft) and 10 × 12 ft (120) total 372 sq ft; with 10% waste that is 409.2 sq ft = 45.47 sq yd, ordered as 46, cut 34.1 ft off the 12-ft roll — one continuous piece the installer seams on site.
Frequently asked questions
How much carpet do I need for a 12 × 15 ft room?
180 sq ft, which with a 10% waste allowance becomes 198 sq ft — exactly 22 square yards, and a 16.5-ft cut from a standard 12-ft roll. Padding matches at 22 sq yd.
Why is carpet sold by the square yard?
Historical convention from the broadloom trade — and it persists because carpet is manufactured in wide rolls. To convert: square yards = square feet ÷ 9. Retailers increasingly quote per sq ft; divide their per-yard price by 9 to compare honestly.
How much waste should I allow for carpet?
Ten percent for plain carpet in rectangular rooms. Fifteen to twenty percent for patterns (the repeat has to match at seams), and expect the installer to confirm — a room slightly wider than the roll forces a seam and a full extra width of material.
Does padding need the same amount?
Yes — padding covers every square foot the carpet does, and it is also rated in square yards. The estimator sizes both from the same with-waste area, so one number orders both.
Two rooms: one order or two?
One order from the same dye lot if the rooms share carpet — the estimator simply adds the areas. Running the rooms separately is right when they get different carpet or the install happens in phases.
🪵 Hard floors instead?
Weighing carpet against hard flooring? The Flooring Calculator counts boxes with waste for laminate, vinyl and hardwood rooms.
Does carpet come in 15-ft rolls too?
Yes — some mills offer 13.5-ft and 15-ft widths, which can eliminate a seam in a wide room and save more than the width premium costs. The estimator's roll-width field runs the length for any of the three.
Is padding thickness or density what matters?
Density. A ⅜-in, 8-lb density pad outlasts a plush ½-in, 4-lb pad under the same carpet, and carpet warranties often specify minimum density. Buy padding by the same square-yard count the estimator gives, at the density the carpet maker names.