The short answer to what size rug pad to buy is a pad set roughly an inch or two in from every edge of the rug, so the pad hides underneath while the rug edges still taper down to the floor without a bulge. That means a 5x8 rug takes a pad trimmed to roughly 4 feet 10 by 7 feet 10, an 8x10 takes an 8 by 10 pad cut back the same way, and a runner takes a narrow pad set an inch in from each edge. Below is how to measure, which size to order, and how to cut a pad down to fit.
Why a rug pad should be smaller than the rug
A pad that reaches all the way to the rug edge, or past it, defeats its own purpose. The lip peeks out around the border, catches the light, and gives a toe or a vacuum wheel something to snag. Keeping the pad about an inch in from every edge lets the rug taper smoothly onto the floor, hides the pad completely, and spreads foot traffic across the backing instead of grinding the rug corners against a hard pad lip. It also slows the wear that shows up first at the edges of a rug.
The rule most guides land on is one to two inches smaller on each side. Start at one inch in if you are unsure, because a pad can always be trimmed further, while a pad that ends up too large cannot be grown back.
What size rug pad to buy for each rug size
Pads are sold under the same rounded size names as rugs, so you order the pad in the nominal size closest to your rug and then trim it back by an inch or so per side. Here is where the common sizes land once you take that inch off each edge.
| Your rug | Pad to order | Trim to about |
|---|---|---|
| 5x8 | 5x7 or 5x8 | 4 ft 10 by 7 ft 10 |
| 6x9 | 6x9 | 5 ft 10 by 8 ft 10 |
| 8x10 | 8x10 or 8x11 | 7 ft 10 by 9 ft 10 |
| 9x12 | 9x12 | 8 ft 10 by 11 ft 10 |
| Runner (about 2.5 by 8) | 2x8 | 2 ft 4 by 7 ft 10 |
The sizes are a starting point, not a law. Because rug names are rounded rather than exact, the only numbers that truly matter are the ones you measure off your own rug, which is the next step.
How to measure before you buy
Lay the rug flat and measure the pile itself, width first and then length, ignoring any fringe or tassels: the pad protects the woven body of the rug, not the trim. Write both numbers down and subtract about two inches from each to get your target pad size, then order the nearest pad that is the same or slightly larger so you have a margin to cut away. If your rug is an odd shape, a round or a runner, measure the widest point in each direction and treat those as your width and length.
How to cut a rug pad to fit
Most pads cut easily at home. Spread the pad on a hard floor, centre the rug face up on top of it, and line up the corners. Mark the pad about one inch inside the rug edge all the way around, either with chalk or a marker on the backing. Lift the rug off, then cut along your marks with sharp household scissors or a utility knife against a straight edge. Lay the rug back over the pad to test the fit, and shave off a little more anywhere the pad still shows. Cutting a touch at a time beats one confident pass that leaves the pad short on one side.
Choosing a pad at Rug Branch
Our pads come in the same size range as the rugs, so you can match one to the rug you already own. The Premium Non-Slip Rug Pad is a low profile PVC pad that grips on both hard floors and carpet and runs from small accent sizes up to the largest room sizes, while the Supreme Non-Slip Rug Pad adds a stronger gripper for rugs that shift a lot, in sizes from a 2 by 8 runner up to 8x11. Both sit low enough to keep the rug edge close to the floor. You can see the full range on the Non-Slip Rug Pads page, and if you are still deciding whether you need one at all, our guide on whether you need a rug pad walks through it. For hard floors in particular, the notes in choosing a pad for hardwood are worth a read before you order.
Mistakes to avoid when sizing a pad
The first slip in working out what size rug pad to buy is ordering the pad in the exact size of the rug and skipping the trim, which leaves a lip showing all around. The second is measuring over the fringe, which pushes your numbers too large. The third is forgetting that a runner needs a narrow pad, not a cut-down rectangle that bunches at the sides. And if a pad arrives a shade too big, that is the easy problem: trim it. A pad that is already too small is the one you cannot fix.
Frequently Asked Questions
Does a rug pad need to match the rug size exactly?
No. A pad should sit an inch or two narrower than the rug on each side so it stays hidden and the rug edge lies flat against the floor. A pad cut to the exact rug size tends to peek out around the border.
What size rug pad do I need for an 8x10 rug?
Order an 8x10 or 8x11 pad and trim it to roughly 7 feet 10 by 9 feet 10, which takes about an inch off each side. That keeps the pad tucked under the rug with no visible edge.
Can you cut a rug pad to fit?
Yes. Lay the pad down, centre the rug on top, mark one inch inside the rug edge, then cut along the line with sharp scissors or a utility knife. Test the fit and shave off more if any pad still shows.
What size rug pad is right for a runner?
Measure the runner across its widest point and along its length, then choose a narrow pad such as a 2 by 8 and trim it an inch in from each edge. A runner needs a long, slim pad rather than a cut-down wide one.
