LED bulbs: what actually changed, and how to buy one now

For decades a 60-watt bulb meant a known amount of light. LEDs broke that link, and the packaging has not made the replacement obvious. Three numbers now do the job.

Lumens: how much light

Lumens measure output. As a rough conversion, the old 40-watt bulb is about 450 lumens, 60 watts about 800, and 100 watts about 1600. Watts on an LED box now tell you only what it costs to run.

For a bedside lamp, somewhere between 400 and 800 lumens is usually right; for a night light, far less.

Kelvin: what colour

2700K matches a traditional warm bulb. 3000K is slightly crisper. 4000K is a neutral white that suits a kitchen. 5000K and above is daylight-shaped and belongs in a workshop rather than a bedroom.

Mixing colour temperatures in one room looks wrong even when nobody can say why, so buy a set at a time.

CRI: how true the colours look

Colour rendering index describes how accurately a light shows colour compared with daylight. Below 80 and skin tones and fabrics look flat and slightly grey. Above 90 they look right.

It costs a little more and it is the difference between a room that feels warm and one that feels like an office.

Dimmable is not automatic

Only bulbs marked dimmable will dim, and even then compatibility with older dimmer switches varies. Symptoms of a mismatch are flickering, a buzz, or a bulb that will not go below half.

Where a lamp has its own touch dimmer, use whatever bulb the manufacturer specifies.

Fittings

E26 is the standard US screw base and covers most lamps. Candelabra fittings are smaller and common in decorative lamps. Check the fitting and, in a small shade, the physical length of the bulb.

Filament-style LED bulbs are attractive in an open fitting and often too long for a compact shade.

Lifespan and what shortens it

LEDs are limited by heat, not by hours of use. A bulb in an enclosed fitting with no ventilation will fail far sooner than the box suggests, and one on an incompatible dimmer sooner still.

If a fitting is fully enclosed, look for a bulb rated for enclosed use; not all are.

Flicker

Cheap drivers can flicker at a rate you do not consciously see but which causes headaches and eye strain over an evening. It is more common at low dim settings. If a bulb is uncomfortable to read under, that is usually why.

Better-quality bulbs state low flicker; it is worth paying for in a room where someone reads.

Buying in one go

Decide the lumens for the job, pick 2700K unless you have a reason not to, choose CRI 90 or above, confirm dimmable and the fitting, and buy the whole room at once so everything matches. The counter on Canal Street stocks the fittings and can tell you what suits a specific lamp.

Smart bulbs, briefly

A smart bulb lets you set brightness and colour temperature by app or schedule, which is genuinely useful for a night routine: warm and dim after a set hour, without anyone remembering to change anything. The cost is a bulb that depends on a network and an account.

If you go this route, check that the bulb still works as an ordinary bulb from the wall switch when the network is down. Ones that do not are a poor choice for a bedroom.

Disposal and what to do with old bulbs

LEDs contain electronics rather than mercury, so they are not hazardous in the way old compact fluorescents were, but they are still electrical waste rather than glass recycling. Most hardware retailers and municipal recycling points accept them.

Old incandescent bulbs can go in general waste; compact fluorescents should not, because they do contain a small amount of mercury and need a dedicated collection point. Keeping a box for dead bulbs and taking it once a year is the simplest system.

Why an LED sometimes fails early

An LED that dies after a few months has almost always been killed by heat or by its power supply rather than by the diode wearing out. Enclosed fittings without ventilation, older dimmer switches and very cheap drivers account for the great majority of early failures.

If bulbs keep failing in one particular fitting, the fitting is the variable, not the bulbs. Try one rated for enclosed use, check the dimmer’s compatibility list, and if it still fails, have the fitting looked at rather than buying a third bulb.

The short version

• Lumens is brightness; watts is only power consumption.
• Kelvin is colour; 2700K is the traditional warm bulb.
• CRI above 90 makes colours look right.
• Check dimmable and check the fitting before buying.

From our shelves

• Cloud Light – Floating Cloud Wall Lamp — $29.95
• Northern Galaxy Light Aurora Projector with 33 Light Effects, Night Lights LED Star Projector — $29.99
• AUVON Plug-in LED Backlit Night Light 4 Packs, Motion & Dusk to Dawn Sensor — $22.99

Where to go next

Browse the full range on the shop page, read the frequently asked questions before ordering, or check delivery timing on the Shipping Policy page. If you would rather ask a person, contact us — the phone reaches the counter.