LED vs Incandescent: Which Bulb Type is Right for You?

The Great Bulb Debate

Walk into any lighting or DIY store and you’ll find shelves of bulbs in dozens of shapes, sizes, and technologies. For most UK homeowners, the key decision comes down to two types: LED and incandescent. While incandescent bulbs have been the standard for over a century, LEDs have rapidly become the dominant choice — and for very good reason.

This guide breaks down the differences clearly so you can make the right choice for your home, your fittings, and your budget.

A Quick Note on Incandescent Bulbs in the UK

It’s worth noting that traditional incandescent bulbs (the classic bayonet and Edison screw types) have been phased out across the UK and EU due to their poor energy efficiency. As of September 2023, halogen bulbs — the last widely available incandescent-type bulb — were also banned from sale in the UK for most applications.

This means that for new purchases, LED is now effectively the only mainstream option for most home lighting. However, understanding why LEDs are superior — and how to choose the right one — is still very much worth knowing.

How They Work

Incandescent Bulbs

Incandescent bulbs work by passing electricity through a thin tungsten filament, which heats up until it glows. It’s a beautifully simple technology — but deeply inefficient. Around 90% of the energy consumed is released as heat, with only 10% converted to visible light.

LED Bulbs

LED (Light Emitting Diode) bulbs work by passing electricity through a semiconductor, which emits light directly with very little heat. This makes them dramatically more efficient — up to 90% of energy is converted to light, with minimal waste heat.

Head-to-Head Comparison

*Based on 3 hours use per day at average UK electricity rate of ~28p/kWh. Incandescent = 60W equivalent; LED = 8W equivalent.

The Real Cost Difference

The upfront cost of an LED bulb is higher than an incandescent — typically £3–8 for a quality LED versus £1–2 for a halogen. But the lifetime cost tells a very different story.

A single 60W incandescent bulb running for 3 hours a day costs approximately £18.90 per year in electricity (at 29p/kWh). An equivalent 8W LED costs just £2.54 per year. Over the LED’s 20,000-hour lifespan, you’d need to replace the incandescent bulb roughly 15 times and spend around £280 more in electricity alone.

For a home with 20 light fittings, switching entirely to LED can save £150–£200 per year on electricity bills.

Light Quality: Does LED Match Incandescent?

Early LED bulbs had a reputation for harsh, cold light that felt clinical compared to the warm glow of incandescent. Modern LEDs have largely closed this gap — but knowing what to look for makes a big difference.

Colour Temperature

Measured in Kelvin (K), colour temperature determines whether a bulb appears warm or cool:

• 2700K — Warm white. Closest to traditional incandescent. Ideal for living rooms, bedrooms, and dining rooms.
• 3000K — Soft white. Slightly crisper than 2700K. Good for kitchens and bathrooms.
• 4000K — Cool white. Bright and clinical. Suited to home offices, garages, and utility rooms.
• 5000K–6500K — Daylight. Very bright and blue-toned. Used in specialist applications.

For most living spaces, 2700K LEDs provide the closest match to the warm, familiar glow of incandescent bulbs.

Colour Rendering Index (CRI)

CRI measures how accurately a bulb renders colours compared to natural daylight (scored out of 100). Incandescent bulbs score around 100. Look for LEDs with a CRI of 90+ for the most natural, flattering light — particularly important in bathrooms, dressing rooms, and anywhere you apply makeup or assess clothing colours.

Dimming

Not all LED bulbs are dimmable. Always check the packaging for a dimmer symbol or ‘dimmable’ label before purchasing. Also ensure your dimmer switch is LED-compatible — older dimmers designed for incandescent bulbs can cause flickering or buzzing with LEDs. LED-compatible dimmers are widely available and inexpensive to retrofit.

Choosing the Right LED Bulb for Each Room

• Living room — 2700K, dimmable, CRI 90+. Warm and flattering for relaxed evenings.
• Bedroom — 2700K, dimmable. Warm light supports the body’s natural sleep cycle.
• Kitchen — 3000K for a bright but warm feel, or 4000K if you prefer a crisper, more functional light.
• Bathroom — 3000K, CRI 90+. Accurate colour rendering is important for grooming tasks.
• Home office — 4000K. Cooler light promotes alertness and concentration.
• Hallway — 2700K–3000K. Welcoming and warm for a first impression.

Bulb Shapes and Fittings

LEDs are available in every shape and fitting type that incandescent bulbs used, including:

• GLS (Globe) — The classic pear-shaped bulb. Available in B22 (bayonet) and E27 (screw) fittings.
• Candle — For chandeliers, wall sconces, and decorative fittings. B15 and E14 fittings.
• Golf ball — Compact round bulb for smaller fittings.
• GU10 spotlight — For recessed downlights and track lighting.
• Filament LED — Designed to mimic the look of vintage Edison bulbs, with visible filament-style LEDs. Perfect for exposed-bulb pendants and industrial-style fittings.

The Verdict

For UK homeowners in 2026, the choice is clear: LED is the right bulb type for virtually every application. They last longer, cost less to run, produce better quality light (when chosen correctly), and are the only type readily available to buy. The key is choosing the right colour temperature, CRI, and dimmer compatibility for each room.

If you’re upgrading your lighting or replacing bulbs in existing fittings, our team at Scarlett Lighting is happy to advise on the best LED options for your specific fittings. Browse our full range of wall lights, pendant lights, and wall sconces — all designed to work beautifully with modern LED bulbs.