Carpet Calculator
Estimate carpet area, roll length, seams, padding, installation and total cost for a room — automatically picks the roll layout (which way the strips run) that wastes the least carpet, with every result shown in both imperial and metric.
Input
Sets the unit every field below is entered in. Results are always shown in both systems.
Feet in imperial, meters in metric.
Feet in imperial, meters in metric.
Standard broadloom widths are 12 ft or 15 ft.
Extra length for seams and trimming — 10% is typical, 15-20% for a patterned or textured carpet that needs pattern matching across seams.
Cost per square yard in imperial, per square meter in metric. Leave blank to skip the carpet cost line.
Cost per square yard in imperial, per square meter in metric, for underlay/padding. Leave blank to skip padding.
Cost per square yard in imperial, per square meter in metric, charged by your installer. Leave blank to skip installation cost.
Output
| Metric | Value |
|---|---|
| No data yet | |
One-line overview of room area, roll length to order and total cost.
More ways to use this tool
REST API
curl -X POST https://api.iotools.cloud/v1/tool/carpet-calculator \
-H "Authorization: Bearer YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"unitSystem": "imperial",
"roomLength": "12",
"roomWidth": "10",
"rollWidthFt": "12",
"rollWidthM": "",
"wastePct": "10",
"carpetPricePerUnit": "35",
"paddingPricePerUnit": "6",
"installCostPerUnit": "8"
}'Swap in your own key from your account. The tool's fields are the body — no wrapper.
Ask an AI agent
Use the IOTools `carpet-calculator` tool (Carpet Calculator) on this input:
YOUR_INPUT_HEREPaste this at any agent connected to the IOTools MCP server, then add your input.
Embed widget
<iframe
src="https://iotools.cloud/embed/carpet-calculator/"
width="100%" height="520" frameborder="0" scrolling="no" loading="lazy"
title="Carpet Calculator — iotools.cloud"
sandbox="allow-scripts allow-forms allow-same-origin allow-downloads allow-popups allow-popups-to-escape-sandbox"
allow="clipboard-write"
style="width:100%;border:1px solid #e5e7eb;border-radius:12px;overflow:hidden"></iframe>
<script src="https://iotools.cloud/embed.js" async></script>Drop this into your own page — free, no key required, just a link back.
| Cost per API/MCP call | From 5 credits |
|---|---|
| Need more credits? | View pricing |
Also available with
Guides
What does this calculator do?
The Carpet Calculator turns a room's dimensions into what you actually need to order: carpet area, roll length, seam count, padding, installation, and a full cost breakdown — for a rectangular room, in imperial or metric units, with every result shown in both unit systems.
Carpet only comes in fixed roll widths (commonly 12 ft or 15 ft, or 4 m/5 m metric), so a room wider than the roll needs two or more strips seamed together. Most calculators just pick one direction to lay those strips; this one checks both directions — strips running along the room's length vs. along its width — and uses whichever needs less total roll length, so you get fewer seams and less wasted carpet without having to work it out yourself.
How the numbers are worked out:
- Strip layout: for each orientation,
strips = ceil(room dimension ÷ roll width), and total roll length =strips × the other room dimension. The orientation needing the shorter total roll length is used (ties go to fewer seams). - Roll-width offcut: because each strip is cut from a full-width roll,
strips × roll width × run lengthis always a bit more than the room's actual area — that leftover is shown on its own line, separate from the waste buffer below. - A waste buffer percentage is added on top of the roll length for seam overlap, pattern matching, and trimming — 10% is a reasonable default; bump it to 15–20% for a patterned or textured carpet.
- Cost: carpet price applies to the full roll length purchased (including the offcut and waste buffer, since that's what you pay for); padding and installation price apply to the room's net area, since both are fitted/charged to the finished floor. All three are optional and shown separately, plus a total — not one opaque number.
Worked example: a 12×10 ft room with a 12 ft roll needs only 1 strip either way (the room fits within the roll width) — no seams. Running the strip across the 10 ft width instead of the 12 ft length means only 10 ft of roll length is needed; plus a 10% buffer that's 11 ft to order (132 sq ft / 14.67 sq yd of carpet, with zero roll-width offcut). At $35/sq yd carpet, $6/sq yd padding, and $8/sq yd installation, that's $700.00 total ($513.33 carpet + $80.00 padding + $106.67 installation) — cheaper than the 12 ft-length layout would have been.
How to use it
- Pick a unit system — imperial (feet, square yards) or metric (meters, square meters). This one toggle sets every field below, so there's no per-field unit guessing.
- Enter the room length and width.
- Enter your carpet roll width — standard widths are 12 ft or 15 ft (imperial), 4 m or 5 m (metric). The calculator automatically works out the strip layout and picks the direction that wastes less carpet.
- Set a waste buffer % — the default (10%) covers ordinary seams and trimming; raise it for a patterned or textured carpet that needs to match across seams.
- Optionally enter carpet, padding, and installation prices per unit area to get a full cost breakdown. Leave any of them blank to skip that line.
The results table updates as you type, with every row showing both imperial and metric so it doesn't matter which one you shop in. Copy or download it as CSV.
Why does it check both strip directions instead of just one?
Because which direction wastes less carpet depends on the room's proportions relative to the roll width, and it isn't always obvious. A long, narrow room might need fewer seams with strips running one way; a wide, short room the other way. Checking both and picking the shorter total roll length means you never end up buying (and paying for) more carpet than the room actually requires.
Does the offcut number mean I need to buy extra carpet beyond what's shown?
No — "Carpet to purchase" already includes it. The roll-width offcut is shown separately so you can see how much of your order is unavoidable trim (from cutting full-width strips to fit the room) versus how much is the waste buffer you chose for seams and pattern matching.
What if I need a different flooring material?
For tile, use the Floor / Tile Area Calculator, which handles grout gaps and box quantities. For a paved surface instead of an indoor floor, use the Asphalt Calculator.
Is my data private?
Yes. This calculator runs entirely in your browser. Your room dimensions, roll width, and pricing are never sent to a server, logged, or stored — the math happens locally on your device.