Measure the widest outside-arm-to-outside-arm width and the height from floor to the top of the back with legs excluded, then check both against the cover’s published range.
Barrel chairs are the worst offenders, because their backs curve and their bottoms often sit narrower than their tops — so the fabric has nothing straight to grip. Two tape measurements, taken twice, prevent almost every fit failure.
Which Two Measurements Actually Decide The Fit?
Width and height decide the fit; seat depth only matters when a product page asks for it. Everything else is a secondary check.
Run the tape from the outer edge of one armrest, across the front of the chair, to the outer edge of the other armrest. That is your widest width. The SureFit measuring guide describes this as outside arm to outside arm, and it is almost always the larger number than the seat itself.
For height, measure from the floor to the highest point of the back. Wayfair’s slipcover guide frames this as bottom of furniture to highest point of back, then tells you to leave leg height out of the fit check. A chair with four-inch legs measured to the top of the legs will look two sizes off on paper.
Two extra numbers come up on some listings: seat depth (front edge of the seat to the backrest) and seat width. Measure both if the product guide lists them. If it doesn’t, skip them.
What Fit Ranges Look Like In Real Listings
Published ranges vary by product and by seller, so the cover’s own chart outranks any general rule you’ve read.
Those numbers describe standard chairs, not barrel chairs, which is exactly why you match your tape to the specific product page instead of to a category.
Two practical habits make the comparison safer. First, buy slightly larger than your chair when you land between sizes, since stretch fabric and manual measurement both drift. Second, measure each dimension twice. A half inch of tape sag changes your answer.
| Measurement | Where The Tape Goes | Why It Matters |
|---|---|---|
| Widest width | Outer edge of one armrest to outer edge of the other | Primary size driver; front width alone undershoots the real number |
| Height, legs excluded | Floor to the highest point of the back, minus leg height | Decides whether the cover reaches the top of the back |
| Seat depth | Front edge of the seat to the backrest | Requested by some product guides; tighter fit at the seat |
| Seat width | Side to side across the seat cushion area | Second fit check on listings that ask for it |
| Bottom circumference | Around the chair’s base, below the seat | Explains why barrel chairs need a zipper or ties to install |
Why Barrel Chairs Slip Without A Closure
A barrel chair cover needs a full-length zipper, ties, or Velcro to stay on, because the chair’s bottom circumference is smaller than its top — the cover cannot slide down over a shape that widens as it rises.
That physics problem is the whole reason slip-fit covers disappoint on curved-back chairs. A rectangle-backed chair narrows at the bottom, so gravity helps you. A barrel chair does the opposite, and any cover without a real closure method has only friction holding it. When you’re comparing options, a cover that lists a zipper or an elastic hem is worth more than one that lists a fabric blend. If you want to see which covers actually include those closures, this roundup of barrel chair covers with secure closures breaks down the tested picks by feature.
Where Most Measurements Go Wrong
The usual mistakes are counting legs, measuring only the front, and treating a barrel chair like a square one.
- Leg height creep: it sneaks into the height number and pushes you into the wrong size.
- Front-only width: the front of a barrel chair is narrower than the widest point across the arms.
- Skipped seat depth: matters on listings that require it for a proper seat fit.
- Rectangle logic: barrel and arc-shaped backs need their curve accounted for, not a flat front measurement.
- No closure method: the most common reason a correctly sized cover still ends up bunched at one side.
- Range mismatch: some guides are written for chairs, loveseats, sofas, recliners, or tub chairs — check that the range applies to barrel chairs at all.
SureFit’s measuring guide covers chairs, loveseats, sofas, and recliners together, which is the pattern to watch for: category ranges that aren’t barrel-specific. Confirm the number fits your chair’s shape before you buy.
Do the two main measurements once, write them down, and compare against the cover’s own chart before anything else. A cover that matches your width and your legless height, and that closes with a zipper, ties, or Velcro, is the one that stays where you put it.
FAQs
Does the armrest width include the fabric or just the frame?
Measure to the outer edge of the arms as they sit now, including whatever upholstery is on them. The cover has to stretch over the finished chair, not the bare frame, so the padded outer surface is your measuring point. If you’re between sizes, go up.
Can I use a regular chair slipcover on a barrel chair?
Usually not well. Standard chair covers are cut for backs that narrow at the bottom, and a barrel chair widens instead, so the fabric has nothing to hold onto. Look for a cover listed for barrel or tub chairs, with a zipper, ties, or Velcro included.
What if my chair sits right on the edge of the size range?
Buy the larger size. Stretch fabric and hand measurements both drift, and product pages commonly allow 0.5″–1″ of error.
References & Sources
- SureFit. “Measuring Guide For Slipcovers | Chairs, Loveseats, Sofas & Recliners” Supports outside-arm-to-outside-arm width and the category-range caveat.
- CRFATOP. “Measure Guide” Source of the 20″–27″ wide and 24″–27″ high barrel chair fit range and the closure requirement.
- Wayfair. “How to Measure for a Slipcover” Supports measuring from the bottom of the furniture to the highest point of the back.
