B10 vs B11 Bulb: What's the Real Difference?
The B10 vs B11 bulb difference is width, and nothing else. A B10 is 1.25 inches wide. A B11 is 1.375 inches wide. Both share the same blunt-tip torpedo shape, and both usually come with an E12 base.
What do "B10" and "B11" actually mean?
Bulb codes look like a secret handshake. They are simple once you split them in two.
- The letter names the glass shape. "B" is the blunt-tip, candle-style torpedo.
- The number gives the widest point of the glass in eighths of an inch. B10 is 10/8 inch. B11 is 11/8 inch (LED Rhythm).
- The base is a separate code, such as E12. It is not part of "B10" or "B11".
Shape and base are independent choices. A B10 can sit on an E12, an E14, or another base (LED Rhythm). Always read both codes before you buy.
B10 vs B11 bulb: side-by-side comparison
| Feature | B10 | B11 |
|---|---|---|
| Widest point (inches) | 1.25 (10/8) | 1.375 (11/8) |
| Widest point (mm, calculated) | 31.75 | 34.925 |
| Shape | Blunt-tip torpedo | Blunt-tip torpedo |
| Typical base | E12 candelabra | E12 candelabra |
| Best for | Small or tightly spaced fixtures | Standard chandeliers and sconces |
Retailers list the same numbers. Bees Lighting gives 1.25 inches for B10 and 1.375 inches for B11, and calls the difference "only in size" (Bees Lighting). Regency Supply lists the same measurements (Regency Supply).
Note on the millimetre row: we calculated it by multiplying each inch value by 25.4. It is not a manufacturer spec.
Are B10 and B11 bulbs interchangeable?
Usually yes. They share the same base and the same silhouette. The gap is one-eighth of an inch (LED Lighting Info).
Watch for these exceptions:
- Small glass shades may publish a maximum bulb diameter.
- Tight candelabra cups can block a wider bulb.
- Multi-bulb chandeliers with narrow spacing can crowd B11s.
Mixing sizes in one fixture is legal, but it looks off. The size gap reads from across a room (LED Lighting Info). Think of it as wearing one brown shoe and one black shoe.
How to choose between B10 and B11
- Check the old bulb. The size is often printed on the glass or the box.
- Check the fixture. Look for a maximum diameter on the shade or in the manual.
- Confirm the base. Pick E12 for North American candelabra sockets. Pick E14 for the standard European size (Bulb Center).
- Match every bulb. Buy one size for the whole fixture.
- Check dimming. Buy a bulb labelled "dimmable" if the circuit has a dimmer (Bees Lighting).
Quick decision guide
| Your situation | Pick |
|---|---|
| Old bulb says B11, open fixture | B11 |
| Tight glass shade or crowded sockets | B10 |
| No size marking, no space limit | Measure the old bulb, then match it |
| Want a bent flame tip | CA10 or CA11 instead |
Base sizes at a glance
| Base | Diameter | Common use |
|---|---|---|
| E11 | 11 mm | Mini candelabra (Europe) |
| E12 | 12 mm | Candelabra (North America) |
| E14 | 14 mm | Small Edison screw (Europe) |
| E26 | 26 mm | Standard medium base |
These figures come from Wikipedia's Edison screw entry and LEDask. The number in an "E" code is the thread diameter in millimetres. Wikipedia also warns that E11 and E12 are not interchangeable.
Why go LED with B10 and B11 shapes?
Most candle-style bulbs sold today are LEDs. The savings are well documented.
- ENERGY STAR-rated LEDs use at least 75% less energy than incandescent lighting (US Department of Energy).
- They last up to 25 times longer (ENERGY STAR).
- Incandescent bulbs release about 90% of their energy as heat, according to figures attributed to the Department of Energy (City of Edmond).
Cooler bulbs also suit small glass shades. Chandeliers, wall sconces, and pendants are the usual homes for B10 and B11 shapes (Regency Supply).
Want to see how lighting fits a whole room? Our guide on cozy home design covers warm, calm spaces. To trim bills further, read how modern window glass can cut energy costs.
Common mistakes when buying candle bulbs
- Confusing shape with base. B11 is the glass. E12 is the screw.
- Assuming every small socket is E12. Some fixtures use E14 or E17 instead (Wikipedia).
- Forcing an adapter. An E12-to-E26 adapter is the generally safe direction. The reverse can exceed the candelabra socket's wattage limit (LED Lighting Info).
- Skipping the dimmer check. A non-dimmable LED on a dimmer may flicker.
- Buying before measuring. Ten seconds with a ruler saves a return trip.
Bulb still not working after a swap? Test the socket before you blame the bulb. Our post on diagnosing the real problem before replacing parts shows the same logic on another appliance.
B10 vs B11 bulb: frequently asked questions
Which is bigger, B10 or B11?
B11 is bigger. It is 1.375 inches wide. A B10 is 1.25 inches wide.
Are B10 and B11 bulbs interchangeable?
Usually, yes. Check the fixture's maximum bulb diameter first. Tight shades are the main trouble spot.
Do both use an E12 base?
Often, yes. The B code only describes the glass, so confirm the base printed on the box.
Can I mix B10 and B11 in one chandelier?
They will work. The size difference may look uneven, so use one size per fixture.
What is the difference between B11 and CA11?
B11 has a blunt tip. CA11 has a bent flame tip. The width story is similar (LED Lighting Info).
Final verdict
- B10 and B11 differ by 1/8 inch of glass width.
- Shape, tip, and base match in most listings.
- Pick B10 for tight spaces and B11 for standard fixtures.
- Match the old bulb, and use one size per fixture.
Sources
- Bees Lighting: B11 and B10 LED candle bulbs
- Regency Supply: Incandescent bulbs and LED retrofits by application
- LED Lighting Info: Are B11 and E12 bulbs interchangeable?
- LED Rhythm: Light bulb shapes, sizes and codes
- LEDask: B11 vs E12
- Bulb Center: Chandelier bulb guide
- Wikipedia: Edison screw
- US Department of Energy: Lighting upgrade guide
- ENERGY STAR: Residential light fixtures at a glance
- City of Edmond: LEDs
B10 vs B11 Bulb: What's the Real Difference?
The B10 vs B11 bulb difference is width, and nothing else. A B10 is 1.25 inches wide. A B11 is 1.375 inches wide. Both share the same blunt-tip torpedo shape, and both usually come with an E12 base.
What do "B10" and "B11" actually mean?
Bulb codes look like a secret handshake. They are simple once you split them in two.
- The letter names the glass shape. "B" is the blunt-tip, candle-style torpedo.
- The number gives the widest point of the glass in eighths of an inch. B10 is 10/8 inch. B11 is 11/8 inch (LED Rhythm).
- The base is a separate code, such as E12. It is not part of "B10" or "B11".
Shape and base are independent choices. A B10 can sit on an E12, an E14, or another base (LED Rhythm). Always read both codes before you buy.
B10 vs B11 bulb: side-by-side comparison
| Feature | B10 | B11 |
|---|---|---|
| Widest point (inches) | 1.25 (10/8) | 1.375 (11/8) |
| Widest point (mm, calculated) | 31.75 | 34.925 |
| Shape | Blunt-tip torpedo | Blunt-tip torpedo |
| Typical base | E12 candelabra | E12 candelabra |
| Best for | Small or tightly spaced fixtures | Standard chandeliers and sconces |
Retailers list the same numbers. Bees Lighting gives 1.25 inches for B10 and 1.375 inches for B11, and calls the difference "only in size" (Bees Lighting). Regency Supply lists the same measurements (Regency Supply).
Note on the millimetre row: we calculated it by multiplying each inch value by 25.4. It is not a manufacturer spec.
Are B10 and B11 bulbs interchangeable?
Usually yes. They share the same base and the same silhouette. The gap is one-eighth of an inch (LED Lighting Info).
Watch for these exceptions:
- Small glass shades may publish a maximum bulb diameter.
- Tight candelabra cups can block a wider bulb.
- Multi-bulb chandeliers with narrow spacing can crowd B11s.
Mixing sizes in one fixture is legal, but it looks off. The size gap reads from across a room (LED Lighting Info). Think of it as wearing one brown shoe and one black shoe.
How to choose between B10 and B11
- Check the old bulb. The size is often printed on the glass or the box.
- Check the fixture. Look for a maximum diameter on the shade or in the manual.
- Confirm the base. Pick E12 for North American candelabra sockets. Pick E14 for the standard European size (Bulb Center).
- Match every bulb. Buy one size for the whole fixture.
- Check dimming. Buy a bulb labelled "dimmable" if the circuit has a dimmer (Bees Lighting).
Quick decision guide
| Your situation | Pick |
|---|---|
| Old bulb says B11, open fixture | B11 |
| Tight glass shade or crowded sockets | B10 |
| No size marking, no space limit | Measure the old bulb, then match it |
| Want a bent flame tip | CA10 or CA11 instead |
Base sizes at a glance
| Base | Diameter | Common use |
|---|---|---|
| E11 | 11 mm | Mini candelabra (Europe) |
| E12 | 12 mm | Candelabra (North America) |
| E14 | 14 mm | Small Edison screw (Europe) |
| E26 | 26 mm | Standard medium base |
These figures come from Wikipedia's Edison screw entry and LEDask. The number in an "E" code is the thread diameter in millimetres. Wikipedia also warns that E11 and E12 are not interchangeable.
Why go LED with B10 and B11 shapes?
Most candle-style bulbs sold today are LEDs. The savings are well documented.
- ENERGY STAR-rated LEDs use at least 75% less energy than incandescent lighting (US Department of Energy).
- They last up to 25 times longer (ENERGY STAR).
- Incandescent bulbs release about 90% of their energy as heat, according to figures attributed to the Department of Energy (City of Edmond).
Cooler bulbs also suit small glass shades. Chandeliers, wall sconces, and pendants are the usual homes for B10 and B11 shapes (Regency Supply).
Want to see how lighting fits a whole room? Our guide on cozy home design covers warm, calm spaces. To trim bills further, read how modern window glass can cut energy costs.
Common mistakes when buying candle bulbs
- Confusing shape with base. B11 is the glass. E12 is the screw.
- Assuming every small socket is E12. Some fixtures use E14 or E17 instead (Wikipedia).
- Forcing an adapter. An E12-to-E26 adapter is the generally safe direction. The reverse can exceed the candelabra socket's wattage limit (LED Lighting Info).
- Skipping the dimmer check. A non-dimmable LED on a dimmer may flicker.
- Buying before measuring. Ten seconds with a ruler saves a return trip.
Bulb still not working after a swap? Test the socket before you blame the bulb. Our post on diagnosing the real problem before replacing parts shows the same logic on another appliance.
B10 vs B11 bulb: frequently asked questions
Which is bigger, B10 or B11?
B11 is bigger. It is 1.375 inches wide. A B10 is 1.25 inches wide.
Are B10 and B11 bulbs interchangeable?
Usually, yes. Check the fixture's maximum bulb diameter first. Tight shades are the main trouble spot.
Do both use an E12 base?
Often, yes. The B code only describes the glass, so confirm the base printed on the box.
Can I mix B10 and B11 in one chandelier?
They will work. The size difference may look uneven, so use one size per fixture.
What is the difference between B11 and CA11?
B11 has a blunt tip. CA11 has a bent flame tip. The width story is similar (LED Lighting Info).
Final verdict
- B10 and B11 differ by 1/8 inch of glass width.
- Shape, tip, and base match in most listings.
- Pick B10 for tight spaces and B11 for standard fixtures.
- Match the old bulb, and use one size per fixture.
Sources
- Bees Lighting: B11 and B10 LED candle bulbs
- Regency Supply: Incandescent bulbs and LED retrofits by application
- LED Lighting Info: Are B11 and E12 bulbs interchangeable?
- LED Rhythm: Light bulb shapes, sizes and codes
- LEDask: B11 vs E12
- Bulb Center: Chandelier bulb guide
- Wikipedia: Edison screw
- US Department of Energy: Lighting upgrade guide
- ENERGY STAR: Residential light fixtures at a glance
- City of Edmond: LEDs
