Buying lighting online means wading through five different numbers, most of which are printed in bold specifically because they sound impressive. Here is what each one means, and which ones you should actually care about.
Watts: what it costs to run
Watts measure power consumed, not light produced. This trips people up because in the old days of filament bulbs, watts were a rough guide to brightness. With LED they are not.
A 20W LED panel can easily out perform a 100W filament bulb. All the watt figure tells you now is what the thing will cost you in electricity.
Care about this if: you are working out running costs, or checking a circuit is not overloaded.
Lumens: total light output
Lumens measure how much visible light a fitting produces in total, in every direction it throws it.
This is the number most retailers lead with, because it is big and comparable. It is genuinely useful when comparing two similar fittings. It is much less useful when comparing two different types, because it says nothing about where the light goes.
A spotlight and a flat panel with identical lumen ratings will produce wildly different rooms.
Care about this if: you are comparing like with like.
Lux: light that actually arrives
Lux is lumens per square metre at a surface. In other words, how much light is actually landing on the thing you are looking at.
This is the honest measure, and it is the one lighting designers use. It accounts for distance, spread and the shape of the fitting.
Rough targets worth remembering:
- Parking and storage: 100 to 150 lux
- General workshop work: 300 lux
- Inspection, detailing and fine work: 500 lux and up
- Office desk work: around 500 lux
There are free lux meter apps for phones. They are not laboratory accurate but they are more than good enough to tell you whether your garage is at 100 or 400.
Care about this if: you want to know whether the room will actually be bright enough. This is the number that matters most.
Kelvin: the colour of the light
Kelvin describes how warm or cool the white is.
- 2700K to 3000K: warm, cosy, orange leaning
- 4000K: neutral
- 5000K to 6500K: cool, crisp, slightly blue
This is a taste and function decision rather than a quality one. Cool for work spaces, warm for social spaces. We have a full guide comparing the two if you are stuck.
Care about this if: you care how the room feels, which you should.
CRI: how accurate colours look
Colour Rendering Index, scored out of 100, measures how faithfully a light source shows colours compared to natural daylight.
Cheap LEDs often sit around CRI 70. Under that light, a red car looks slightly muddy, a navy panel can read as black, and subtle differences in finish vanish. Decent LEDs sit at CRI 80 or above. Good ones reach 90 plus.
For a garage used for storage, CRI is irrelevant. For anything involving paint, colour matching, wrapping, photography or filming, it is arguably the most important spec on the page and the one most likely to be missing from a cheap listing.
If a product does not state its CRI, assume it is low.
Care about this if: you detail, spray, wrap, film content, or just want your car to look like its actual colour.
Beam angle and diffusion
Less commonly quoted but worth understanding. Beam angle describes how widely light spreads from the fitting. Narrow angles concentrate light, wide angles spread it.
Flat diffused panels like hexagon lighting have a very wide spread by design, which is why they produce such even coverage. It is also why comparing their lumen figure directly against a narrow floodlight is misleading in both directions.
IP rating: how weatherproof it is
Two digits. The first covers dust, the second covers water. IP20 means indoor only. IP44 shrugs off splashes. IP65 handles jets of water.
An attached domestic garage almost never needs more than IP20. A detached garage that gets damp, or a unit with a washbay in it, absolutely does. Do not fit an indoor rated panel above a space where cars get pressure washed.
The four numbers to check before you buy
If you remember nothing else from this page, check these.
- CRI, ideally 80 or higher, 90 plus for detailing
- Kelvin, matched to what the room is for
- Lumens, compared against similar fittings only
- IP rating, matched to how damp the space gets
Watts tell you the bill. Lux tells you the truth. Everything else is marketing.
Frequently asked questions
Is a higher lumen figure always better?
No. Too much light in a small space is uncomfortable, and badly distributed light is worse than less light spread well.
What CRI do professional detailers use?
Most serious paint correction lighting is CRI 90 or above. Anything lower risks missing defects that show up in daylight.
How do I measure lux at home?
A phone app held at working height gives you a workable estimate. Take readings in several spots to find your dark corners.
Every kit in our hexagon lighting collection lists its full specification. If a number you need is missing, ask us and we will tell you straight.