To measure arc floor lamp reach, ignore the width on the listing and work out where the shade's centre lands from the edge of the base, because the base is what stands against your wall or your sofa arm. Take the listed width, subtract half the shade, and you have the distance from the back edge of the base to the middle of the shade. Then measure your room from where the base can actually stand to the middle of the seat you want lit. If the first number is bigger than the second, the light lands where you sit.
Key takeaways
- The listed width is not the reach. It runs from the far edge of the shade to the far edge of the base. On our Cosmo that is 102.7cm, and the dome's centre sits about 87cm from the back of the base.
- The pole is not in the middle of the base. On all three of our factory drawings it sits 6 to 10cm behind centre, which is why pole to shade figures worked out from the width come up short.
- Measure from where the base can stand to where you sit. Beside the arm, that is the arm width plus about 30cm. Behind the sofa, add a gap at least as wide as the base.
This guide is about the measuring. For why an arc beats a straight pole over a sofa, how much base weight it needs and which room suits which shape, start with our arc floor lamp guide. For whether a lamp actually lights a page once it is in place, run the test in our floor reading lamp guide. Height against the ceiling has its own rule in our floor lamp sizing guide, so it is not repeated here.
What the listing gives you, and what it means
A floor lamp listing usually gives you a height, a width, a shade diameter and a base diameter. The one that causes trouble is the width. On every arc lamp we have measured, the width is the whole footprint: from the outer edge of the shade on one side to the outer edge of the base on the other. It tells you how much floor the lamp uses. It does not tell you how far the light reaches, because the shade's centre is half a shade in from that outer edge, and the base's centre is half a base in from the other.
Some listings, ours included, then add a reach figure, pole centre to shade centre. Those figures are often worked out from the width by taking off half the shade and half the base, which assumes the pole rises from the middle of the base. Ours don't. On the factory drawings for the Cosmo, the Orsay and the Rousseau, the pole meets the base 6 to 10cm behind its centre, so the arc starts further back and reaches further forward than the arithmetic says.
So there are three horizontal numbers worth knowing, and you can get all of them from a dimension drawing or a straight on product photo:
| Number | What it is | How to get it from a listing |
|---|---|---|
| Reach (B) | Pole centre to shade centre | Width, minus half the shade, minus the distance from the pole to the far edge of the base. If you can't see where the pole meets the base, assume the middle and treat the answer as the low end. |
| From the back of the base (C) | Back edge of the base to shade centre. The number for a base standing against a wall. | Width minus half the shade. No guessing needed. |
| From the front of the base (D) | Front edge of the base to shade centre. The number for a base standing against a sofa arm. | Width minus half the shade, minus the base diameter. |
C is the safe one to take from any listing, because it needs only the width and the shade size. It is also the one most people actually need.
Our arc lamps, measured off the factory drawings
We took the dimension drawing for each lamp, the one on its product page, and measured it pixel by pixel: where the pole meets the base, how wide the base and the shade are drawn, and where the shade's centre falls. Scaling from the labelled base and shade diameters, the two scales agree within about 1% on every drawing, so the numbers below are good to a centimetre or two.
| Lamp | Listed width (A) | Reach, pole to shade centre (B) | From the back of the base (C) | From the front of the base (D) |
|---|---|---|---|---|
| Cosmo Chrome Marble Base 183cm, 30cm dome, 32cm base |
102.7cm | about 81cm | about 87cm | about 55cm |
| Orsay Gold Arc 173cm, 25cm dome, 25cm base |
71.5cm | about 52cm | about 59cm | about 34cm |
| Rousseau Rattan Weave 169cm, 32cm drum, 25cm base |
48.6cm | about 26cm | about 32cm | about 7cm |
| Flore Black Arc (pre order) 195cm, 40cm drum, 28cm marble base |
not yet published | roughly 80cm* | roughly 90cm* | roughly 60cm* |
Heights and bases
| Lamp | Shade rim off the floor (E) | Where the pole meets the base |
|---|---|---|
| Cosmo | about 138cm | 6cm in from the back edge of the 32cm base |
| Orsay | about 140cm | 6cm in from the back edge of the 25cm base |
| Rousseau | about 134cm | 7cm in from the back edge of the 25cm base |
| Flore | around 160cm* | near the centre of the 28cm marble base, from the photo |
*Flore has no factory drawing yet. Its figures are estimated from the straight on product photo, scaled three ways (height, base and shade), which spread them by about 5cm either side. We will replace them with drawing figures when the November stock lands. Cosmo and Orsay product pages quote about 70cm and about 46cm of reach; those were worked out from the width with the pole assumed central, and the drawings show the pole further back. Use the drawing figures here, or the width minus half the shade, and you will not be caught short.
Two things stand out. The Cosmo and the Orsay are true arcs: their shades land well past the front of the base, so they can stand beside an arm or behind a sofa and put light over the seat. The Rousseau is a bridge arm, not an arc. Its shade centre sits about 7cm past the front of the base, which is why our rattan floor lamp guide tells you to park it beside your seat rather than over it.
The tape test: three measurements in your room
You need a tape measure and a strip of painter's tape. Everything is measured on the floor, because that is where the base lives.
- Decide where the base can stand. There are only two honest answers with a sofa. Beside the arm, on the floor next to it, with the base's front edge touching the arm. Or behind the sofa, with the base's back edge on the wall, which means pulling the sofa out by at least the base diameter plus a couple of centimetres: 34cm for a Cosmo, 27cm for an Orsay. A base cannot go under a sofa, and it should not sit half on a rug edge.
- Mark the spot you want lit. Put the tape on the floor directly under the middle of the seat you will sit in, about 30cm forward of the back cushion. For a reading chair, mark under the middle of the seat cushion. This is where the shade's centre should end up, because an open dome drops its light almost straight down.
- Measure between them. Beside the arm: from the outer face of the arm to your mark. On most New Zealand sofas that is the arm width, 15 to 25cm, plus about 30cm into the first seat, so 45 to 55cm. Behind the sofa: from the wall to your mark, which is the gap, plus the back of the sofa (about 20cm), plus about 30cm, so 80 to 90cm with a Cosmo sized gap.
- Compare with the lamp. Beside the arm, use the lamp's D number. Behind the sofa, use its C number. If the lamp's number is within about 10cm of your mark, the light lands on your lap. If it is short by more, the light lands on the arm or behind your shoulder, which is fine for a side table and useless for a book.
- Check the height of the rim. Stand on your mark. The Cosmo's rim hangs about 138cm off the floor and the Orsay's about 140cm, so an adult walking under either one meets it at chest to chin height. The shade must hang over a seat, never over the way people walk to it. Sitting down, your head is about 130cm off the floor, so keep the shade forward of your head, over your lap, not above it.
A worked example
Say the sofa is 90cm deep with 20cm arms and 60cm wide seats, and you read in the seat nearest the window. Beside the arm, your mark is 20cm of arm plus 30cm into the seat: 50cm from the arm face. A Cosmo puts its dome centre about 55cm past the arm face, 5cm forward of the mark, over your lap. An Orsay puts its dome about 34cm past the arm face, which is 16cm short, over the front of the arm and your shoulder rather than the book. Behind the sofa, with the sofa pulled out 34cm, the mark is 34 plus 20 plus 30, about 84cm from the wall. A Cosmo's dome lands about 87cm out, right on it. An Orsay behind a sofa, with its own 27cm gap, lands about 59cm out, over the back cushion, which lights the room nicely and lights the reader from behind.
Five ways people buy short
- Reading the width as the reach. A 102.7cm width sounds like a metre of reach. It is a footprint. Take half the shade off before you compare it with anything.
- Assuming the pole is in the middle of the base. Look at the drawing or the photo. On ours it is 6 to 10cm behind centre, and on many arcs the counterweight sits behind the pole for the same reason.
- Measuring to the front of the sofa instead of to the seat. You do not sit on the front edge. Mark the floor under the middle of the seat and measure to that.
- Forgetting the base needs its own floor. Behind a sofa, the gap has to be at least the base diameter, plus room for the cord to leave the base. Where the cord runs after that is in our cable management guide.
- Hanging the shade over the walkway. A rim at 134 to 140cm is a head height for children and a chest height for adults. If the only way to reach the seat puts the shade over the path to it, choose the other placement or a longer arc.
The lamps in this guide
Cosmo Chrome Marble Base Floor Lamp
183cm tall, 102.7cm listed width, 30cm chrome dome, 32cm marble base. Dome centre about 87cm from the back of the base and about 55cm from its front. The longest reach we stock.
173cm tall, 71.5cm listed width, 25cm gold dome, 25cm base. Dome centre about 59cm from the back of the base and about 34cm from its front. Right for an armchair or the end of a sofa.
195cm tall, 40cm linen drum, 28cm marble base. Drum centre roughly 90cm from the back of the base on our photo estimate, with the drawing figure to follow. Available on pre order at the time of writing.
Rousseau Rattan Weave Floor Lamp
169cm tall, 48.6cm listed width, 32cm woven drum, 25cm base. A bridge arm: the drum centre sits about 7cm past the front of the base. Beside a seat, not over it.
All of our arcs are together in the arc floor lamps collection, each with its dimension drawing on the product page.
Frequently asked questions
What does reach mean on an arc floor lamp?
Reach is the horizontal distance from the centre of the pole to the centre of the shade. It is not the listed width, which runs from the far edge of the shade to the far edge of the base and includes half a shade and a whole base that never reach anywhere. For placing the lamp, the more useful figure is the distance from the edge of the base to the shade's centre: width minus half the shade for a base against a wall, and that minus the base diameter for a base against a sofa arm.
How far does an arc floor lamp need to reach over a sofa?
Far enough to put the shade's centre over the middle of the seat you sit in. With the base beside the arm, that is the arm width plus about 30cm, so 45 to 55cm from the arm face on most New Zealand sofas. With the base behind the sofa, it is the gap behind the sofa plus about 20cm of back plus about 30cm, so 80 to 90cm from the wall. A Cosmo covers both; an Orsay covers a single armchair or the end of a sofa.
Is the width on an arc lamp listing the same as its reach?
No. The width is the lamp's footprint, from the outer edge of the shade to the outer edge of the base. Reach is pole centre to shade centre, and it is shorter than the width by half the shade plus the distance from the pole to the far edge of the base. On our Cosmo the width is 102.7cm and the reach about 81cm; on the Orsay 71.5cm and about 52cm.
How much room does an arc floor lamp need behind a sofa?
At least the base diameter plus a couple of centimetres, so the base sits flat on the floor with its back edge near the wall and the cord can leave it. For a Cosmo that is about 34cm, for an Orsay about 27cm. Pull the sofa out by that much, then measure from the wall to the middle of the seat and compare it with the lamp's back of base to shade centre figure.
Can an arc floor lamp hang over a walkway?
Not comfortably. The shade rim on our arcs hangs 134 to 140cm off the floor, which is head height for a child and chest to chin height for an adult. Plan the placement so the shade ends up over a seat, with the way people walk to that seat passing beside the base rather than under the shade. If the only placement that reaches the seat crosses the path, choose the other placement or a longer arc.
Measured your room?
Browse our arc floor lamps, each with its dimension drawing on the product page. Lamps are couriered NZ wide at the live rate shown before you pay, or collect from our Albany showroom at Unit B, 19 Arrenway Drive, Rosedale, open seven days. Lamps never need freight: Mainfreight carries our large mirrors, not these. Afterpay and Zip available. NZ designed, NZ owned.
