Broadloom yards, seams, pad and tackless strip for a room — sized to roll width, not just area.
Estimates are planning aids, not a professional quote. Double-check quantities and product coverage — and any local code or permit requirements — before you buy.
⚠ Lay every breadth with the pile leaning the same direction — pile that runs opposite ways reflects light differently, and the seam between mismatched directions shows as a visible color band even when it's cut and joined perfectly.
⚠ Pull the old tack strip and every staple before laying new pad — a staple left behind telegraphs through new pad and carpet as a hard lump underfoot.
| Flooring | $648–$877 |
| Fasteners & Hardware | $20–$26 |
| Total | $668–$904 |
Excludes tools, delivery, tax and permit fees. Labor not included — this is a DIY materials estimate.
These are affiliate links: we may earn a commission if you buy through them, at no extra cost to you. It never changes what the calculator recommends — the shopping list comes from your dimensions, not from what pays.
About this calculator
Enter your room's length and width and the Carpet Calculator works out how it actually gets ordered off a broadloom roll — how many 12 or 15 ft wide breadths your room needs, how much length each breadth loses to waste and fit, and the whole order converted to square yards, the unit carpet is bought and installed in. It seams the pad the same way and figures tackless strip around the room's perimeter instead of pricing the floor as one flat area.
Pick a carpet type, whether to add pad and its thickness, and how many doorways need a transition strip, and every quantity updates together, including extra carpet, pad and tackless strip for a straight flight of stairs. It's a planning estimate — actual seam placement, pile direction and roll width vary by supplier, so confirm your carpet's real roll width before ordering.
Step by step
A step-by-step walkthrough to go with your plan above. Follow the product instructions and any local code or permit requirements as you work.
Measure the room and run the calculator to see how many breadths your roll width forces and where the seam will fall. Plan the seam to run with the main traffic path, not across a doorway.
Pull up the old carpet, pad and every staple down to the bare subfloor, and pry off the old tackless strip if it's damaged. Leftover staples telegraph through new pad as hard lumps.
Install new tackless strip around the entire perimeter, about 1/2 in off the wall, with the angled pins facing the wall. Skip it across doorways, which get a transition strip instead.
Roll out pad to the inside edge of the tackless strip and staple it every few inches, butting seams tight without overlapping. Trim it flush at the strip so it doesn't ride up the pins.
Roll out each breadth with a few extra inches of trim margin, and where two breadths meet, join them with hot-melt seam tape and a seam iron so the pile direction matches on both sides.
Use a knee kicker to hook the carpet onto the tackless strip along two adjoining walls, then power-stretch it toward the remaining walls to remove all slack before hooking those edges.
Run a wall trimmer along every wall to cut the carpet to the exact wall line, then tuck the trimmed edge down into the gap between the tackless strip and the baseboard with a stair tool.
Wrap and tack stair carpet tread by tread from the top down, and install transition strips at every doorway to cap the raw edge where the carpet meets another floor.
Equip the job
Hand-picked categories that match the shopping list above. Links open a current selection so you can compare brands and prices.
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Interior & Finishing
Answers
It isn't just length times width. Carpet comes off a roll that's 12 or 15 ft wide, so if your room is wider than the roll you need a second breadth seamed in, and each full breadth is cut to your room's length plus a waste allowance for fit and pile matching. This calculator divides your room's width by the roll width to get the breadth count, then converts the total cut length to square yards — the unit carpet is actually sold and installed in.
A breadth is one full-width strip cut from the roll and rolled out across the room; a room needs as many breadths as it takes to cover its width. A 12 ft wide room needs one 12 ft breadth with no seam; a 14 ft wide room needs a second breadth, seamed in, even though only 2 extra feet of width are used — the leftover width from that second breadth is waste you're still paying for. A wider 15 ft roll can sometimes avoid a seam a 12 ft roll would need.
Yes for nearly every install — pad cushions each step, insulates the floor and roughly doubles how long the carpet itself wears before it flattens and needs replacing. Standard 1/4 in rebond pad is the right call for most rooms and most carpet types. Thicker premium pad feels plusher underfoot but can raise the finished floor height enough to bind an interior door on its frame, so check door clearance, especially in a room you're recarpeting over an existing hard floor elsewhere in the house.
Stairs are cut narrower — this calculator assumes a standard 3 ft stair width rather than the full roll — and each step needs roughly one and three-quarter feet of carpet length to wrap the tread, the riser and a bit of turn allowance. Stairs also get their own tackless strip at the back of every tread and the base of every riser, and installers often use thinner, firmer pad (or skip pad entirely) on stairs, since thick cushioned pad underfoot on a step is a fall hazard.
Cut pile (plush or saxony) has yarn tips sheared level and shows a smooth, soft surface that's a good all-around choice for bedrooms and living rooms. Berber loop leaves the yarn looped rather than cut, which resists crushing and wears well in high-traffic areas but shows vacuum and snag marks more. Frieze (or shag) uses a longer, twisted yarn that hides footprints and vacuum lines especially well, which suits busy family rooms. All three take the same breadth-and-seam math — the type mainly changes cost per yard and how the surface wears.