The answer in two lines
The base on your fixture decides the bulb, not the room. E27 and E14 are Edison-screw bases where the number is the thread's outside diameter in millimetres: E27 = 27 mm, E14 = 14 mm (Wikipedia). A GU10 spot has a twist-and-lock two-pin base and does not fit a screw socket (Philips Hue). Read the marking on the fixture or old bulb, and choose power in lumens, not watts (ENERGY STAR). Final installation should be done by a qualified electrician.
You need a new bulb and the shelf shows E27, E14 and spot bulbs. The wrong one will not fit or, worse, fits and overheats the fixture. In this guide, Tawredaat (توريدات), an Egyptian supplier of electrical and finishing materials serving Cairo and Giza (FAQ here), explains what the names mean and how to choose base, shape and power, based on named public sources and with no prices.
What do E27, E14 and GU10 mean?
The E stands for Edison and the number is the thread's outside diameter in millimetres (Wikipedia). The screw turns into the socket. E27 and E14 are used in continental Europe and China at 220-240 V. GU10 is different: a twist-and-lock base with two pins 10 mm apart, designed for 240 V (Philips Hue).
| Name | Meaning | Size / shape | Typical use |
|---|---|---|---|
| E27 | Edison screw, 27 mm | 27 mm screw thread | Standard 230 V lamps (Wikipedia) |
| E14 | Small Edison screw, 14 mm | 14 mm screw thread | Candelabras, chandeliers, night lamps (Wikipedia) |
| GU10 | Twist-and-lock two-pin base | Pins 10 mm apart, bulb about 50 mm wide | 240 V spot, no transformer (Philips Hue) |
| MR16 / GU5.3 | Spot with two thin pins | About 2 in (5 cm) wide | 12 V spot that needs a 12 V transformer (Philips Hue) |
Note: these dimensions come from Wikipedia and Philips Hue; lamp caps are covered by IEC 60061 (per Wikipedia). Our product pages do not list these dimensions, so match the base by what is marked on your fixture.
How do I find the base I have at home?
- ✔ Switch the power off at the breaker before removing any bulb, and let it cool.
- ✔ Look at the old bulb or its box: it is usually marked E27, E14 or GU10.
- ✔ If it is not marked: the wider screw is usually E27 and the smaller one E14. Confirm by measuring or comparing with a known bulb before buying a quantity.
- ✔ For a spot fitting, check whether it is 220-240 V (GU10) or 12 V (MR16) with a transformer. They are not interchangeable (Philips Hue).
- ⚠ If unsure, photograph the bulb and fixture and ask an electrician before you buy.
E27, E14 or spot: which one for each place?
The golden rule: the fixture chooses. You can change the shape and power of the bulb, but the base must match the fixture. This table shows common use:
| Place / fixture | Usual base | Note |
|---|---|---|
| Table lamp, simple pendant or ordinary ceiling fitting | E27 (often) | Standard 230 V lamp (Wikipedia) |
| Chandelier, small lamp or wall sconce | E14 (often) | Used in chandeliers and small lamps (Wikipedia) |
| Recessed or hanging spot | GU10 (220-240 V) or MR16 (12 V) | Read the fitting: they are not interchangeable (Philips Hue) |
| Enclosed fixture (glass or plastic cover) | Per the fixture | Choose a bulb marked suitable for enclosed fixtures (1000Bulbs) |
This is common use, not a fixed rule: there are chandeliers with E27 and lamps with E14. What matters is the base marked on your own fixture.
12 V or 220 V spot: what is the difference?
- ✔ GU10: runs on 240 V mains directly, no transformer (Philips Hue).
- ✔ MR16: 12 V and needs a 12 V transformer (Philips Hue).
- ⚠ A GU10 bulb will not work in an MR16 fitting or the other way round: base and voltage differ (Philips Hue).
- ⚠ The product page of our "220V spot (fork)" does not state the base type (we do not say it is GU10), so check the base on the box or listing and compare it with your fixture before buying.
Should I choose power in watts or lumens?
According to ENERGY STAR and the U.S. Department of Energy, brightness is measured in lumens, not watts. The rule: find the lumens you need and choose the lowest wattage that provides them. Their words: "think lumens, not watts". The package also shows lumens and colour temperature in Kelvin.
| Old incandescent bulb (watts) | Minimum lumens to look for |
|---|---|
| 40 W | 450 lumens |
| 60 W | 800 lumens |
| 75 W | 1,100 lumens |
| 100 W | 1,600 lumens |
| 150 W | 2,600 lumens |
This table is the ENERGY STAR benchmark. Our bulb pages state watts only (5, 6, 9, 12 and 15 W) and no lumens, so read the lumens on the box or ask our team before comparing two bulbs. Without a recognised public source, we do not give a fixed wattage per room.
Can I put an LED bulb in an old fixture?
Usually yes if the base matches, but watch two things:
- ✔ Never exceed the maximum marked on the fixture. Excess wattage can melt the shade or degrade the wiring and may cause a fire (NY State DHSES).
- ✔ That limit is compared with the LED bulb's actual wattage, not its "equivalent". If the fixture does not say whether the limit is for incandescent or LED, ask the fixture manufacturer (Waveform Lighting).
- ✔ An enclosed fixture traps heat and can shorten an LED's life, so choose a bulb marked suitable for enclosed fixtures (1000Bulbs).
- ⚠ If a bulb overheats or you smell burning, switch off the breaker and call an electrician.
- ⚠ If you will use a dimmer, the bulb must be dimmable. See our LED dimmer guide. Our bulb pages do not say they are dimmable.
And if you are choosing warm or white light, see our LED colour temperature guide.
LED bulbs available at Tawredaat
These products are active and in stock now. Check the base on your fixture before buying; what a page does not state (base, lumens, dimmability) we do not claim:
| Product | What the product page says |
|---|---|
| Luma 15W A60 E27 warm LED bulb | E27 base, warm light, 15 W |
| Luma 5W E14 cool white LED bulb | E14 base, white light, 5 W, 4-year warranty |
| Luma 9W warm LED bulb | Warm light, 9 W, 4-year warranty. The page does not state the base |
| Luma 12W cool white LED bulb | White light, 12 W, 4-year warranty. The page does not state the base |
| Luma 6W frosted filament candle LED bulb | Frosted filament candle, 6 W, warm white, for chandeliers and sconces. The page does not state the base |
| Luma 220V LED spot (fork) | 220 V, white light, for focused accent lighting. The page does not state the base type |
See all bulbs in the bulbs collection (tawredaat.com/collections/bulbs).
Frequently asked questions
What does E27 mean?
E is for Edison and 27 is the thread diameter in mm, so a screw base 27 mm across (Wikipedia).
What is the difference between E27 and E14?
Size: E27 is 27 mm and E14 is 14 mm, and they do not fit each other's sockets (Wikipedia).
What is a GU10 spot?
A spot bulb with a twist-and-lock two-pin base, 240 V, no transformer (Philips Hue).
Can I put GU10 in an MR16 fitting?
No, voltage and base differ and they are not interchangeable (Philips Hue).
Watts or lumens?
Lumens. Find the lumens you need and choose the lowest wattage that gives them (ENERGY STAR).
Can I use a bulb with higher power than the fixture's label?
No. Do not exceed the fixture's marked maximum because heat can damage the shade and wiring (NY State DHSES).
Can I change the bulb myself?
A simple bulb swap is possible after switching the breaker off, but any work on the fixture or wiring should be done by a qualified electrician or engineer.
Do you deliver?
Tawredaat delivers in Cairo and Giza only.
Ready to choose your bulb?
See LED bulbs at Tawredaat, with delivery in Cairo and Giza.
About Tawredaat: Tawredaat (توريدات) is an Egyptian supplier of electrical and finishing materials, serving homeowners, companies and contractors in Cairo and Giza. Questions? See our FAQ.
English summary: E27 and E14 are Edison-screw bases where the number is the thread diameter in mm (27 mm and 14 mm); GU10 is a twist-and-lock two-pin spot base for 240 V mains and is not interchangeable with 12 V MR16 (Wikipedia, Philips Hue). Match the base to the fixture, choose power by lumens rather than watts (ENERGY STAR, U.S. DOE), never exceed the fixture's maximum wattage (NY DHSES), and have a qualified electrician do final installation.
Sources
- Wikipedia, Edison screw (E = Edison and the number is the thread's outside diameter in mm: E27 = 27 mm, standard 230 V lamps; E14 = 14 mm, used for candelabras, chandeliers and night lamps; E27 and E14 are used in continental Europe and China at 220-240 V; lamp caps are covered by IEC 60061) — en.wikipedia.org/wiki/Edison_screw
- Philips Hue, MR16 vs GU10 bulbs (GU10: 240 V mains, twist-and-lock base with 10 mm pin spacing, about 50 mm diameter, no transformer; MR16: 12 V, needs a 12 V transformer, 2-inch diameter, GU5.3-type pins; the two are not interchangeable) — philips-hue.com/en-gb/explore-hue/blog/mr16-bulb-vs-gu10-bulb
- ENERGY STAR, Learn about brightness (brightness is measured in lumens, not watts; find the lumens you need and choose the lowest wattage; minimum lumens for common incandescent bulbs: 40 W = 450, 60 W = 800, 75 W = 1,100, 100 W = 1,600, 150 W = 2,600) — energystar.gov/products/lighting_fans/light_bulbs/learn_about_brightness
- U.S. Department of Energy, Lumens and Lighting Facts ("think lumens, not watts"; the Lighting Facts label lists lumens, lifespan and colour temperature in Kelvin) — energy.gov/energysaver/save-electricity-and-fuel/lighting-choices-save-you-money/lumens-and-lighting-facts
- New York State Division of Homeland Security and Emergency Services, fire safety bulletin on light fixtures (do not exceed the fixture's maximum rated wattage: the excess heat can melt the shade or degrade the wiring and may cause a fire; check the label or manual before replacing a lamp) — dhses.ny.gov/system/files/documents/2025/07/cfs-bulletin-light-fixtures.pdf
- Waveform Lighting, LED bulb exceeding fixture or socket wattage rating (the fixture's maximum applies to the bulb's actual wattage, not its equivalent rating; if the fixture does not say whether the rating is for LED, CFL or incandescent, ask the fixture or socket manufacturer) — waveformlighting.com/home-residential/can-you-install-an-led-bulb-that-exceeds-its-fixture-or-socket-wattage-rating
- 1000Bulbs, What is an enclosed fixture rating (heat shortens the life of LED bulbs; a bulb not rated for enclosed fixtures may overheat; the enclosed rating appears on the packaging or datasheet) — blog.1000bulbs.com/home/what-is-an-enclosed-fixture-rating
- Tawredaat product pages (Luma 15W A60 E27 warm; Luma 5W E14 cool white; Luma 9W warm; Luma 12W cool white; Luma 6W frosted filament candle; Luma 220V LED spot fork 26124: the pages state the base only for the 15W bulb (E27) and the 5W bulb (E14), give no lumens, and do not state dimmability) — tawredaat.com/collections/bulbs
