Light Bulb Moment

[lankeela]

I need to replace a couple of table lamp light bulbs so need the equivalent of the old 40 watt bulbs - but I can't make head nor tail of the new bulb wattages - what do I need to look for?

[woofgang]

https://www.thelightbulb.co.uk/resources/how-to-find-the-right-light-bulb-step-by-step-guide/

[bookbinder]

https://www.any-lamp.com/lumen-to-watt/40-watt-in-lumens

[TonyV]

What sort of fitting is it screw or bayonet, but they normally have equivalent wattage alongside new rating.

[ummmm]

As Tony says they usually show the watt.

[Old_Geezer]

Look for equivalent lumens rather than watts. The internet has tables giving equivalence.

[ladybirder]

Do what I used to do. Just take the old bulb with you to a decent shop and they will give you the correct replacement.

[Buenchico]

As O_G suggests, you should be forgetting about Watts (after an initial conversion in order to give you a reference point) and thinking in terms of Lumens.

So you should be looking for bulbs producing around 400 lumens:
https://www.easy-lightbulbs.com/lighting-guides/the-difference-between-watts-and-lumen/

[woofgang]

Buenchico is right but you also need to think about light temperature...the actual colour of the emitted light. Yellow light ie warmer and cosier, white light may be better for working but can be cold and casts harsher shadows.
https://www.thelightbulb.co.uk/resources/colour_temperature/

[lankeela]

No wonder I am confused!

[Buenchico]

>>> you also need to think about light temperature

Agreed. That's measured in Kelvin and you should see it shown on the side of the box. Fortunately though there's usually a graphic to go with it, which tends to make things a lot clearer without having to bother too much about numbers!

If you want to see how the numbers relate to colour temperature though, this is a good guide:
https://lightingdesignstudio.co.uk/wp-content/uploads/2017/10/Lighting-colour-temperature.jpg

[woofgang]

lankeela once you know what you like though, just make a note of the settings!

[Buenchico]

Forgetting all about the theory though, if you actually sent me out shopping and told me that you wanted a couple of bulbs to replace old 40W ones in table lamps, here's what I'd probably come back with:
https://groceries.asda.com/product/bayonet-cap-light-bulbs/asda-led-filament-classic-40-w-bayonet-cap-frosted-light-bulbs/1000101555706

[AZardoz]

Hah ! ASDA bulb - not up to snuff:

* Beam angel: N/A