The best arc floor lamps

Most lamps light the space around where they stand. An arc lamp is different: its base stands at the edge of the room and the head curves out to hang over something - a sofa, a chair, a coffee table - where no table or floor lamp could go.

That makes reach the specification that decides whether one works. An arc that falls short leaves its light over the arm of the sofa rather than the middle of it, and at that point you have bought an awkward floor lamp.

The comparison against a torchiere and a tripod lamp is in torchiere vs arc vs tripod; the short version is that an arc lights a zone from above, while a torchiere lights the whole room from a corner.

Brightech Sparq - the pick for a chair or loveseat. An integrated 3000K LED on a 45 inch reach that publishes its output - 680 lumens in black, 850 in silver - with a foot-pedal dimmer stepping 100, 50 and 30 percent, on a weighted 9 inch base. Publishing output is rare for an arc lamp, and the foot pedal means you dim it without leaning over the sofa.
Cons: 45 inches reaches an armchair or loveseat but falls short of the middle of a three-seat sofa; the integrated LED fixes the color temperature; and three dimming steps rather than stepless.

Brightech Trilage - for light over a sofa, with bulbs you choose. Three standard sockets on an arc, so the base stands at the room's edge while the heads reach out over the seating. Standard sockets mean you decide the light - put high-CRI bulbs in it and it beats most integrated-LED lamps on color.
Cons: publishes no output because there is nothing to publish; you buy three bulbs separately; and the heads hang at seated eye height, so they must be dimmable or shaded.

Philips Ultra Definition, 1,500 lm - the bulbs for the Trilage. 1,500 lumens at 2700K with CRI 95. In a three-socket arc, three of these give you far more light than any integrated arc, with excellent color.
Cons: three at 1,500 lm is a lot over a sofa - dimming is essential.

Lutron Credenza plug-in dimmer - to dim a socketed arc. A socketed arc lamp with dimmable bulbs dims through a plug-in dimmer with no wiring.
Cons: it sits at the outlet, not beside the sofa.

Check the ceiling first. Most arc lamps want at least 8 feet of clearance to arc without the shade touching the ceiling. Under a lower ceiling, the arc either cannot open fully or ends up hanging too low over the seating. In a room with sloped ceilings the arc can be the right answer, reaching out from the tall side - see attic and loft lighting.

Insist on a heavy base. All the weight of the head is cantilevered out over the sofa, so the base is a counterweight. Weighted cast iron or solid steel keeps it standing; a light base is a tipping risk, especially with children or pets.

Hang the head at the right height. Low enough to light the seating, high enough that nobody standing up hits it and nobody seated looks straight into the bulb. The height rules for reading light are in where to put a floor lamp.

Pair it with an uplight. An arc lights the sofa zone; a torchiere in a corner lights the room. Together they cover the ambient and task layers - see best floor lamps for a living room.