2026 Update: if you are still comparing a 100W incandescent bulb with a 10W LED bulb, the short answer is simple. The LED uses far less power, but the real buying decision is not just about wattage. You still need to check the cap type, bulb shape, colour temperature and whether the fitting is dimmable.
That matters in South African homes because old fittings are still common. Some use B22, some use E27, and some rooms have a mix of old and new bulbs that were never meant to live together. If you want the cleaner replacement path, start with the LED Light Bulbs & Globes collection and work from there.
Key takeaways
- A 10W LED bulb usually draws much less power than a 100W incandescent bulb.
- Wattage tells you power draw, not the full story.
- Check the cap type before you buy. E27, B22 and GU10 are not interchangeable unless you are using the right adaptor.
- Choose Warm White, Cool White or Daylight based on the room, not just the number on the box.
- If the bulb will sit in an exposed fitting, check the shape and look as well as the fitting type.
What the comparison really means
Incandescent bulbs waste a lot of energy as heat. LED bulbs are much more efficient, which is why most people move away from incandescent lamps as soon as they can. In plain terms, the LED does the same basic job with far less power.
That does not mean every 10W LED bulb is the right replacement for every old 100W bulb. Light output, beam spread, colour temperature and the way the bulb sits in the fitting all matter. A bulb can be efficient and still feel wrong in the room if the light is too harsh or the cap type is off.
| Bulb type | What it is good at | What to check before buying |
|---|---|---|
| 100W incandescent | Old-school warm light and legacy fittings | Whether you are ready to move away from the higher power draw and extra heat |
| 10W LED bulb | Lower power use, cooler running and modern replacement lighting | Cap type, bulb shape, colour temperature and dimming compatibility |
Do not buy on watts alone
Wattage is only part of the job. It tells you how much power the bulb uses, but it does not tell you whether the bulb will fit the lamp, whether the finish suits the room or whether the light colour will feel comfortable at night.
For example, 3000K is Warm White, 4000K is Cool White and 6000K is Daylight. A bedroom usually feels better with Warm White. A utility area or work space may feel sharper with Cool White or Daylight. The right answer depends on where the bulb will be used.
If you want a straightforward replacement option, compare products in the Decorative LED Bulbs collection as well, especially where the bulb is visible and style matters as much as output.
Open LED bulbs Check a lamp holder adaptor
What to check before you replace an old bulb
If you are replacing a bulb in an older fitting, check these points before you order:
- Cap type: E27, B22 and GU10 are different. Do not guess.
- Shape: A60, globe and filament styles all look and behave differently.
- Colour temperature: Warm White, Cool White or Daylight should suit the room.
- Dimming: Only buy a dimmable bulb if the fitting and dimmer are meant for it.
- Exposure: If the bulb is on display, the finish matters as much as the fitting.
A useful example is the LED A60 Bulb 9W - Warm White 3000K. It is a cleaner modern bulb shape for a standard replacement job, but you still need to confirm that the cap type and colour suit your fitting.
When a lamp holder adaptor makes sense
Sometimes the bulb is not the real problem. The fitting is. If you are working with an older cap type and you want to move to a different bulb family, a lamp holder adaptor may help. That only makes sense when the adaptor matches the fitting and the new bulb setup.
If you are unsure, do not improvise. Check the fitting first, then the bulb, then the adaptor. The Lamp Holder Adaptor: E27 - B22 is a practical example of the sort of product people use when the old and new cap types do not line up.
Why the old bulb still matters in the comparison
The second bulb image keeps the comparison visual and shows the kind of modern replacement people are choosing. The LED replacement is not just about saving electricity. It is about using the right bulb for the room, the fitting and the way you actually live.
If you are replacing a visible bulb in a pendant, table lamp or feature fitting, compare the look as well as the wattage. The Decorative LED Bulbs collection is usually the better place to start for those jobs.
For a simpler everyday replacement, the 5W Warm White LED E27 Bulb Non-Dimmable is another useful reference point. Just make sure the cap type and colour temperature suit the room before you buy.
Where this matters most in South African homes
In South Africa, a lot of bulb buying still happens as a quick replacement. The old bulb fails, someone runs to buy a new one, and the packaging gets chosen too fast. That is how you end up with the wrong cap type, a bulb that looks too cold in the bedroom or a dimmable bulb on a non-dimmable circuit.
It is worth taking one extra minute to check the details. A good replacement bulb should fit properly, give the right colour of light and suit the room without any fuss. That is usually more useful than chasing the biggest wattage saving on paper.
Browse LED bulbs View a standard LED A60 bulb
FAQ
Is a 10W LED bulb always the right replacement for a 100W incandescent?
No. It is usually a much lower-power choice, but you still need to check the cap type, shape, dimming and colour temperature before you buy.
What colour temperature should I choose?
Use Warm White for softer rooms, Cool White for general indoor work and Daylight when you want a brighter, crisper feel. Pick the one that suits the room.
Can I use an LED bulb in an old lamp holder?
Yes, if the cap type and physical shape match. If they do not match, you may need the correct lamp holder adaptor.
Why does the LED bulb feel like a better buy?
Because it uses less power and runs cooler than the old incandescent bulb, which makes it a more practical choice for everyday use.
Where should I start if I am replacing old bulbs in the house?
Start with the LED Light Bulbs & Globes collection, then check cap type, colour temperature and whether you need a dimmable bulb.
