How much clearance does a robot vacuum need to fit under furniture?
Sofa makers sometimes print the gap under the frame, robot makers print a height, and a few robots now change theirs on the way in.
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The gap under a sofa is a number, and on three sofas from one IKEA catalog it changes by more than four inches. The height under furniture is 2 3/8 inches for the FINNALA sofa, 4 3/8 inches for the VISKAFORS and 6 3/4 inches for the UPPLAND. That is the space a robot vacuum has to drive into.
Now put a robot beside them. The Qrevo 2 Pro stands 3.80 inches tall. It passes under the UPPLAND with nearly three inches to spare and under the VISKAFORS with a little over half an inch. It cannot get beneath the FINNALA at all.
Does your robot fit under your sofa? Whatever it can’t get under, it can’t clean, and that floor stays yours to do by hand. No robot vacuum height quoted below is as low as the FINNALA’s 2 3/8 inches, including the models built to be slim. And on some of them, the height itself moves.
The part on top sets the height
Most robot vacuums map a room with a spinning laser rangefinder, called LiDAR or an LDS. The laser needs a clear line of sight in every direction, so it usually sits in a raised disk on the lid, above everything else. However tall the bin, battery, motor and wheels make the body, the disk adds its own height on top.
The Saros 10 shows what that disk costs, because its laser can drop into the body. The same robot has two heights: 3.68 inches with the laser up and 3.14 inches with it down. The raised sensor adds about half an inch, roughly a seventh of the robot’s full height.
Roborock calls the system RetractSense and says it “lowers its LDS to pass under low-clearance areas and rises again in open spaces.” An upward range finder sets the sensor’s height for low-clearance areas. A top contact sensor, in Roborock’s words, “prevents forced entry and surface scratches.”
Dreame builds the same idea into the X50 Ultra. With its retractable dToF sensor lowered, the robot’s height drops to 3.5 in, about 3.5 inches. Dreame gives no height with the sensor raised, and that is the figure that applies wherever the robot keeps it up.
Term
dToF sensorShort for direct time-of-flight. The sensor sends out a pulse of laser light and times how long it takes to bounce back from a surface, which gives the distance to that surface. Dreame and Ecovacs use the name for the navigation laser that Roborock calls an LDS.The Saros 10R does away with the rising part altogether. It stands 3.1 in tall, the same 3.14 inches as the Saros 10 with its laser lowered. It steers with a solid-state LiDAR, a 3D time-of-flight sensor and an RGB camera, and no part of it spins above the lid.
Which height on the spec sheet to read
One listing can carry several heights, and only one of them is the robot. The Deebot X8 Pro Omni’s spec sheet gives the robot’s height, the station’s and the outer carton’s. Only the first meets your sofa, and its 3.9 in works out to 3.86 inches.
A retracting sensor puts two heights on the spec sheet, and the lower one holds only where the robot decides to lower its laser. On the Saros 10, the upward range finder makes that call by reading the edge ahead. If your sofa clears the raised height, the robot goes under either way. If it clears only the lowered height, every pass depends on that reading being right.
When a robot fits and still stays out
Even the Saros 10R, tied for the lowest height in the table, balked at first. In a hands-on review published in February 2025, one reviewer wrote that the robot “refused to go under furniture like the couch and dining table” on its first runs.
On the third attempt it went under both, and the reviewer did not see the problem again. The couch and the table had the same clearance on every run. Clearance only lets a robot under. The robot still has to judge the opening from outside and decide to go in.
A thin margin also has to absorb everything a single published figure leaves out. A sofa’s front rail is not always its lowest point, since a center leg or a cross rail farther back can sit lower. A rug under the furniture lifts the robot by the depth of its pile.
And a robot climbing a rug edge or a threshold tilts nose-up for a moment, raising its front above its listed height. A little over half an inch, the Qrevo 2 Pro’s room under the VISKAFORS, has to cover all of it.
The clearance a robot vacuum needs, then, starts at its tallest listed height, which on a model with a retracting sensor is the height with the sensor up. Among these five robots that runs from 3.14 inches to 3.86. The gap to compare it with is the lowest one under the sofa, across its full depth, with the rug in place.
For the FINNALA the comparison is short. At 2 3/8 inches, it sits about three-quarters of an inch below the slimmest height any of these makers lists. Whatever rolls under it stays there until someone reaches in by hand.
