Our shop rule is about one kilogram of salt lamp for every ten square metres of room. Measure the room, length times width, and read off the band. Most people take home a 2 to 3 kg lamp, because it fills a main bedroom or a small lounge from one side table with warmth to spare. Big room? Two smaller lamps beat one giant one. Here is the room-size table, what each weight looks like in real rooms, and the bulb each size takes.
Last updated September 2026
On this page: Room size to lamp weight · Each weight in a real room · Two lamps or one · Which bulb · Choosing your lamp · Questions
What size salt lamp do you need for your room? ☀️
Start with a tape measure, not the lamp. Pace out the room or measure it: a 3 m by 4 m bedroom is 12 m², and a 5 m by 7 m open-plan lounge is 35 m². Then use our shop rule of thumb: about 1 kg of lamp for every 10 m² of room.
Treat the rule as a floor, not a ceiling. A lamp glows brightest close up, so if you sit across the room from it, go up one band. That is why the 2 to 3 kg lamp is our most popular size. It gives a normal bedroom one band of headroom.
| Room size | Lamp weight | Typical room | Rivendell range (NZ$, checked 18 September 2026) |
|---|---|---|---|
| Up to about 20 m² | 1–2 kg | Nightstand, desk, single bedroom, nursery | 1–2 kg lamp NZ$39.99, or the 1.5–2 kg low-voltage lamp NZ$49.99 |
| About 20–30 m² | 2–3 kg | Main bedroom (with headroom), small lounge, home office | 2–3 kg lamp NZ$49.99 |
| About 30–45 m² | 3–4.5 kg | Living room, open-plan kitchen and dining | 3–4.5 kg lamp NZ$59.99 |
| Over 45 m², long or L-shaped | Two or three lamps, or 4.5 kg and up | Big open-plan living, a lounge that runs into a dining room | Two 1–2 kg or 2–3 kg lamps in different corners, or one large salt lamp: the 4.5–6 kg lamp (NZ$69.99) was sold out online at our check |
What does each weight look like in a bedroom, lounge and office?
Salt lamps are hand-cut from rock salt, so two lamps of the same weight can differ in shape. Weight is still the honest guide, because it tells you how much glowing salt is in the room. Here is how each band sits in a real home.
1–2 kg: the nightstand lamp 🕯️
This is the lamp for a bedside table, a desk corner or a child's room. It throws a small pool of amber light, enough to read a page by and to fall asleep beside. On a nightstand it leaves room for a book and a glass of water.
The 1–2 kg lamp comes with a 15 W bulb and a switch lead. Its twin, the 1.5–2 kg low-voltage lamp, stands about 17 cm high and runs on a 12 V lead with its own 12 W bulb. Parents often choose it as a nursery night light.
2–3 kg: the bedroom and small-lounge lamp 🌙
Put a 2 to 3 kg lamp on a chest of drawers or a side table and the whole bedroom turns amber at dusk. In a small lounge it holds its own beside the sofa without taking over the surface. This is the size most people take home, and the one we hand to anyone who says "I just want a salt lamp".
The 2–3 kg Rivendell Edition lamp comes with a 15 W bulb and a certified switch lead. Add a dimmer lead if you want it to fade to a night light.
3–4.5 kg: the living-room lamp ✨
From 3 kg up, a salt lamp stops being a bedside glow and becomes a feature. On a sideboard or a low side table it warms a living room or an open-plan kitchen and dining space. Give it a firm, level surface and a felt pad or coaster underneath, and leave it where you put it. Heavy salt does not like being carried about.
The 3–4.5 kg lamp comes with a 15 W bulb and a certified switch lead, and it is the biggest size in stock online at our check.
4.5 kg and up: the large salt lamp
Above 4.5 kg you are buying a presence, not a night light. These lamps suit a big open-plan room, a hallway console or a shop counter. At our September check the 4.5–6 kg lamp (NZ$69.99) was sold out online. The 5–7 kg, 7–10 kg and 15–20 kg lamps live in the shop at Westfield Manukau rather than on the website, because at that weight you want to see the piece before you carry it home. Ask us and we will send photos.
The home office
A desk wants a small lamp at the edge of your eye line, not a boulder beside the keyboard. The 1–2 kg lamp or the 1.5–2 kg low-voltage lamp is right for a desk or a study nook. If the office is a full room you also relax in, the 2–3 kg lamp on a bookshelf suits it better. For a desk with no spare surface, the caged salt lamp (16 cm across) or the 10 cm salt lamp pyramid gives the same glow in a tidy shape.
When do two small lamps beat one big one? 🔮
A salt lamp lights the corner it sits in. It does not flood a room like a ceiling light. So the question is not only "how big" but "how many corners".
- Long, L-shaped or open-plan rooms. One lamp at each end spreads the glow where one big lamp would leave the far end dark.
- A bedroom that is also a reading nook. A 1–2 kg lamp on the nightstand and a 2–3 kg lamp on the drawers give you a night light and an evening glow on separate switches.
- Surfaces and cables. Two small lamps fit on shelves and side tables that would never hold 5 kg, and each stays close to its own power point.
- The price sum. Two 1–2 kg lamps come to about NZ$80, against NZ$59.99 for one 3–4.5 kg lamp. You pay a little more for two, and you get two corners lit.
Choose one big lamp when you want a single focal point on a sideboard or hall console, and the room has one obvious place for it.
Which bulb does each size take? 💡
Here is the rule that surprises people: the bulb follows the lead, not the kilograms. Rivendell sells two systems, and the label on your lamp or lead always wins.
| Lamp | Lead | Bulb |
|---|---|---|
| 1–2 kg, 2–3 kg, 3–4.5 kg standard lamps | Mains switch lead | 15 W E14 small Edison screw |
| 1.5–2 kg low-voltage lamp, 4.5–6 kg lamp | 12 V lead | 12 W bulb only; the listing warns that any other bulb will blow the lead |
| Any standard mains lamp from 1.5 kg up on a dimmer lead | Dimmer lead | 15 W or 30 W E14, whichever the lamp's own label allows |
WorkSafe New Zealand's rule for every lamp in the house applies here: fit the wattage the fitting is rated for, and never a higher wattage than recommended, because a hot bulb can burn the fitting. Screw the bulb in firmly, since a loose bulb runs hot too. If you run two lamps across a room, check the cords for damage now and then.
Why does the bulb matter for size? Rock salt is thirsty. Sodium chloride pulls water from the air, and the warmth of the bulb is what keeps the lamp dry. A lamp that is switched off for weeks in a damp Auckland winter can sweat and drip, and a bigger lamp has more surface to sweat from. The fix is not a hotter bulb than the lead allows. It is leaving the lamp on, and a coaster underneath. Our salt lamp care guide covers weeping, flickering and cleaning.
Keep a spare 15 W bulb in the drawer, and a 30 W bulb if your big lamp sits on the dimmer lead.
Choosing your lamp 💎
At our 18 September 2026 check, a first salt lamp starts around NZ$40 for the 1–2 kg size, the popular 2–3 kg lamp is around NZ$50, and the 3–4.5 kg living-room lamp is around NZ$60. Spare bulbs are under NZ$10 and the dimmer lead is around NZ$20. A large salt lamp above 4.5 kg is a shop visit or a phone call.
The lamps on the website ship NZ-wide, and if you are in Auckland the lamps are lit on the shelf at Rivendell, Shop 62, Westfield Manukau, so you can stand back and judge the glow yourself.
🌙 In the tradition, a salt lamp is the hearth of a room: the warm point everything else settles around. Pick the size for the room you actually sit in at dusk. See the salt lamps in stock and choose your band. If you want to know what owners say a lamp does for a room, our salt lamp benefits guide tells it warmly.
Salt lamp size questions
Is a 2–3 kg salt lamp big enough for a bedroom?
Yes. By our rule a 12 to 15 m² bedroom needs 1.2 to 1.5 kg, so a 2–3 kg lamp gives you a band of headroom. It fills the room with amber from a chest of drawers and still dims to a night light on a dimmer lead.
Can a salt lamp be too big for a room?
Only in the practical sense. A 4.5 kg lamp on a nightstand crowds the table and sits too close to your eyes when you read. In a small room a big lamp also has more surface to sweat if it is left off. Choose the band for the room, and go up one only if you sit far from it.
Does a damp room need a bigger lamp?
No. Size does not dry a lamp; the bulb's warmth does. Salt draws moisture from the air, so a switched-on lamp usually stays dry and a switched-off one weeps. Keep the lamp on, keep it out of the bathroom, and put a coaster under it.
What size salt lamp suits an office desk?
The 1–2 kg lamp or the 1.5–2 kg low-voltage lamp. It sits at the edge of the desk, glows softly beside the screen, and leaves the work surface free. If the office doubles as a sitting room, go to 2–3 kg on a shelf.
Sources
Room-size rule, prices and stock from Rivendell's live listings and our salt lamp guides, checked 18 September 2026. Bulb wattage and cord safety from WorkSafe New Zealand. The water-attracting nature of salt from RSC Education; bulb warmth and lamp sweating from a salt lamp supplier's bulb guide. Prices can change; the product page is always current.