Quick answer: Yes, an LED can replace a 4-pin CFL when the replacement matches the socket and electrical arrangement: Type A uses a compatible ballast, Type B bypasses it, and Type A+B supports either arrangement. Ledvance's pin-base lamp guide describes these options.
Start with the base code and how the fixture supplies power, then compare light output and running costs. This guide focuses on choosing a replacement; it does not provide fixture rewiring instructions.
What does a 4-pin bulb mean?
The pin count describes the lamp's connections, not a universal replacement specification. Ledvance identifies G24Q as a four-pin base and G24D and GX23 as two-pin bases in its ordering guide. Record the complete base designation from your existing lamp rather than shopping by appearance alone.
According to Wikipedia's compact fluorescent lamp article, a non-integrated plug-in CFL keeps its ballast in the luminaire, so replacing the tube normally leaves that ballast in place. That explains why a replacement decision involves the fixture as well as the bulb.
Use this reference to narrow the search:
| Base designation | Pin count | What the source establishes |
|---|---|---|
| G24q / GX24q | Four | Current lists these sockets for its SpectraChoice Type B lamp. Current specification |
| G24d | Two | Ledvance identifies this as a two-pin designation. Ledvance ordering guide |
| GX23 | Two | Ledvance identifies this as a two-pin designation. Ledvance ordering guide |
| 2G11 | Four | According to Ledvance, its OSRAM DULUX L LED serves this separate base on an electronic ballast. OSRAM DULUX L guide |
Treat the table as an identification aid. Select a lamp that explicitly lists your base and the intended electrical arrangement; a pin-count match alone does not establish both.
Which replacement type should you choose?
Choose Type A to retain a compatible ballast, or Type B for a ballast-bypass conversion. Type A+B offers both operating arrangements, as described in Ledvance's lamp guide.
| Lamp category | Power arrangement | Buying decision |
|---|---|---|
| Type A | Ballast compatible | Match the lamp to the retained ballast. Ledvance guide |
| Type B | Ballast-free, directly supplied from line voltage | Plan for the specified bypass arrangement. Ledvance guide |
| Type A+B | Supports ballast-compatible or ballast-free operation | Decide which supported arrangement the fixture will use. Ledvance guide |
According to Current, its Type B conversion eliminates the ballast-compatibility check because the fixture is wired to bypass the ballast. Its SpectraChoice plug-in is rated for 120–347 VAC in that arrangement. Those are specifications for that product, not every lamp with the same pins. Current specification
Use a qualified electrician for ballast bypass or any other mains-voltage fixture modification. Keep your own task to recording labels and choosing a compatible product. Our LED ballast guide provides additional background on the component involved.
How much light should the replacement produce?
Compare the listed lumens before choosing wattage. Lumens describe light output; watts describe electrical power. There is no need to invent a fixed wattage conversion when the replacement guide gives a specific lamp pairing.
According to Ledvance, these are Type A replacement examples from its range:
| Listed CFL replacement | LED lamp power | Listed LED output |
|---|---|---|
| CF26DD/E, a 26 W CFL | 9.5 W | 960–1,100 lumens for the colour-temperature-selectable version; 1,200 lumens for the 9.5 W omnidirectional version. Ledvance lamp guide |
| CF32DT/E or CF42DT/E, 32 W or 42 W CFLs | 15 W | 1,900–2,000 lumens. Ledvance lamp guide |
Use these as named product examples, not a rule that every CFL of that wattage takes the same LED. Make a shortlist using the compatibility information, then compare each candidate's stated output. Enter the candidates' actual figures in the bulb comparison tool, replacing its sample inputs before judging the results.
For electricity estimates, distinguish lamp power from complete system power. According to Ledvance, one listed CF26DD/E ballast system draws 54 W, compared with 19 W for its LED system. These are the manufacturer's system figures, not the wattage of an individual lamp. Ledvance system comparison
Worked example: monthly electricity savings
With the assumed inputs below, the reduction is $0.84 per system per month. This is an arithmetic illustration, not a measured result or a promised saving.
Assumed inputs: one complete system, old system power of 54 W, replacement system power of 19 W, operation for 4 hours per day and 30 days per month, and electricity at $0.20/kWh. The assumed powers use the manufacturer comparison above; the schedule and rate are chosen solely for this example. Ledvance system comparison
The electricity cost calculator uses these formulas:
- Total watts = power per system × quantity.
- Daily energy = total watts × daily hours ÷ 1,000.
- Monthly energy = daily energy × days per month.
- Monthly cost = monthly energy × electricity rate.
Here is every step for the assumed inputs:
| Calculation | Existing system | Replacement system |
|---|---|---|
| Total power | 54 × 1 = 54 W | 19 × 1 = 19 W |
| Daily energy | 54 × 4 ÷ 1,000 = 216 ÷ 1,000 = 0.216 kWh | 19 × 4 ÷ 1,000 = 76 ÷ 1,000 = 0.076 kWh |
| Monthly energy | 0.216 × 30 = 6.48 kWh | 0.076 × 30 = 2.28 kWh |
| Monthly cost | 6.48 × $0.20 = $1.296 | 2.28 × $0.20 = $0.456 |
Monthly saving = $1.296 − $0.456 = $0.840, or $0.84. Use the unrounded costs for subtraction. Purchase and installation costs are excluded; without those inputs, this calculation cannot establish a payback period. When entering complete system watts, count systems in the quantity field so you do not count their lamps again.
Checklist before ordering
Build a short record for each fixture so the purchase decision is traceable:
- Copy the existing lamp's full designation and base code.
- Record the ballast model if you intend to retain it.
- Write down the selected replacement's operating category and supported arrangement.
- Compare the candidate's listed lumens with the output you want.
- Keep lamp wattage and complete system wattage in separate fields.
- Save the product compatibility information alongside the order.
Resolve any missing compatibility information before buying multiple replacements. A completed checklist should identify a particular lamp and operating arrangement, rather than just a search term.
FAQ
Can I replace a 4-pin CFL with an LED?
Yes, when the LED supports the existing base and the chosen ballast arrangement. Type A, Type B, and Type A+B offer different routes, as described in Ledvance's pin-base guide.
Does Type A mean it works with any ballast?
No; select a compatible ballast-and-lamp pairing. According to Ledvance, its OSRAM DULUX L LED requires an electronic ballast and a check against its ECG compatibility list, and is not for conventional magnetic ballasts. OSRAM DULUX L guide
Does a Type B bulb require ballast bypass?
Yes. According to Current, its Type B lamp requires the existing fixture to be wired to bypass the ballast; inserting a different bulb is not the complete conversion. Current specification
Is 2G11 the same base as G24q?
No: it is a separate four-pin base. According to Ledvance, its OSRAM DULUX L LED is intended for 2G11 with an electronic ballast, so use the full base designation when choosing a replacement. OSRAM DULUX L guide
What LED wattage replaces a 26 W CFL?
According to Ledvance, its listed CF26DD/E replacements are 9.5 W Type A LEDs delivering 960–1,100 lumens (colour-temperature-selectable version) or 1,200 lumens (omnidirectional version). That is a specific replacement example, not a universal wattage conversion. Ledvance lamp guide
Jack Shi
Founder & editor, LEDaskJack Shi builds and writes LEDask, an independent LED-lighting tools project operated by clooms. He designs the calculators, checks their formulas and reference values against published engineering data, and writes the guides across the site.
