Rug Size Calculator – Find Your Perfect Rug Size
A rug can pull a whole room together — or it can make the room look smaller than it is. The difference is almost always the size.
Rug Size Calculator
Leave about 18 inches of bare floor around the rug. Sizes are in feet, and the answer is always a standard shop size.
Too small, and the sofa and chairs float around it like separate islands. Too big, and it swallows the floor and hides the shape of the room. Designers use one simple rule: leave about 18 inches of bare floor around the rug, and let the front legs of your main furniture sit on it. This free rug size calculator takes your room measurements and your room type, and tells you the standard rug size to buy — the size that fits with the right border, suits how the room is used, and is actually sold in shops.
How to Use This Calculator
Example
Let us work through a real room. Your living room is 12 feet wide and 15 feet long. First the border: 18 inches is 1.5 feet on each side, so the rug can be at most 12 minus 3, which is 9 feet wide, and 15 minus 3, which is 12 feet long. The standard sizes in shops are 4 by 6, 5 by 8, 6 by 9, 8 by 10, 9 by 12, 10 by 14, and 12 by 15 feet. The largest standard size that fits inside 9 by 12 is 9 by 12 itself — so you would buy a 9 by 12 foot rug, place it so the front legs of the sofa sit on it, and enjoy an even 18-inch border of bare floor all the way round. Now try a smaller room: a bedroom 10 feet wide and 12 feet long allows at most a 7 by 9 foot rug, and the largest standard size inside that is 6 by 9 — a lovely fit under the lower two-thirds of the bed.
Standard Rug Sizes
Rug shops sell a short list of standard sizes: 4 by 6, 5 by 8, 6 by 9, 8 by 10, 9 by 12, 10 by 14, and 12 by 15 feet. The calculator only recommends from this list, so the size you get is one you can actually buy — no custom order, no awkward trimming. If your room is very small or oddly shaped, the calculator will say so, and a small 4 by 6 rug or a runner is usually the better answer than squeezing in a big one that touches the walls.
The Bottom Line
A rug that fits does two quiet jobs at once: it frames the furniture and it shows off the floor. The 18-inch border is what makes the room look bigger instead of smaller, and the front-legs rule is what makes the seating feel like one group instead of pieces that drifted apart. Measure the room once, pick the room type, and buy the standard size the calculator recommends — it is always the largest size that still fits, never the one that crowds the walls. Get the size right once, and the rug will look like it was made for the room. Get it wrong, and no pattern or colour will quite fix it, so take the two minutes to measure and calculate before you shop.
Frequently Asked Questions
Why leave 18 inches of bare floor around a rug?
The border frames the rug the way a frame suits a picture. It shows the floor, makes the room look bigger, and stops the rug looking like wall-to-wall carpet. A rug that touches the skirting on every side loses that framed effect and makes the room feel cramped.
Should all four legs of the sofa be on the rug?
Front legs are enough for most living rooms, and that is what this calculator is built around. All four legs on the rug is the fuller, more luxurious look, but it needs a rug one size bigger — try the next size up and check the border is still at least a foot. In a dining room, all four chair legs must be on the rug, plus 24 inches past the table.
What is the most common rug size for a living room?
For an average living room, 8 by 10 feet is the most common choice, and 9 by 12 fits larger rooms. Small living rooms usually take a 5 by 8. If your calculator result is 8 by 10, you are in very good company — it is the size most rug shops sell the most of.
What size rug goes under a queen bed?
An 8 by 10 foot rug is the usual answer for a queen bed. It slides under the lower two-thirds of the bed and reaches about two feet past each side and the foot, so your feet land on rug when you get up. For a king bed, step up to 9 by 12.
What size rug do I need under a dining table?
Take the table size and add 24 inches on every side, so chairs stay on the rug even when someone pulls one out to sit down. In practice, a table for six usually needs an 8 by 10 foot rug, and a table for eight usually needs 9 by 12. Measure your table, not just the room, before you buy.
What if my room is too small for a standard rug?
Then the calculator will tell you no standard size fits with an 18-inch border. Do not force a big rug in — buy a small 4 by 6 foot rug instead, or a runner for a narrow room or hallway. A small rug with a proper border always looks better than a big rug squeezed wall to wall.
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