How many lights can I have on a 6 Amp circuit?

A standard 6A circuit at 230V can handle up to 1380 Watts. If you are using 5W LED bulbs, you could theoretically have 276 bulbs. However, practical limits on cable length and voltage drop usually mean sticking to a more reasonable number (e.g. 15-20 fittings per circuit).

What is 'Diversity' in electrical loading?

Diversity is the assumption that not all electrical appliances or lights will be turned on at the same time. For domestic lighting, the UK standard (OSG) allows for a 66% diversity factor when calculating the total load of the installation, though individual circuits are usually calculated at 100% load.

Can I use a 10 Amp breaker for lighting?

While 10A breakers are sometimes used, the standard for UK domestic lighting is 6A. Using a higher-rated breaker requires that the cables (usually 1.0mm or 1.5mm) are capable of handling that current under all conditions, including when run through insulation.

Why do LEDs use less power?

LEDs (Light Emitting Diodes) convert almost all the energy they receive into light. Older incandescent bulbs wasted 90% of their energy as heat. This is why a 5W LED can produce the same brightness as a 50W halogen bulb.

How many lights can I have on a 6 Amp circuit?

A standard 6A circuit at 230V can handle up to 1380 Watts. If you are using 5W LED bulbs, you could theoretically have 276 bulbs. However, practical limits on cable length and voltage drop usually mean sticking to a more reasonable number (e.g. 15-20 fittings per circuit).

What is 'Diversity' in electrical loading?

Diversity is the assumption that not all electrical appliances or lights will be turned on at the same time. For domestic lighting, the UK standard (OSG) allows for a 66% diversity factor when calculating the total load of the installation, though individual circuits are usually calculated at 100% load.

Can I use a 10 Amp breaker for lighting?

While 10A breakers are sometimes used, the standard for UK domestic lighting is 6A. Using a higher-rated breaker requires that the cables (usually 1.0mm or 1.5mm) are capable of handling that current under all conditions, including when run through insulation.

Why do LEDs use less power?

LEDs (Light Emitting Diodes) convert almost all the energy they receive into light. Older incandescent bulbs wasted 90% of their energy as heat. This is why a 5W LED can produce the same brightness as a 50W halogen bulb.

Lighting Load Calculator

Plan your electrical circuit capacity and safety.

Number of Light Fittings

Wattage per Bulb (W)

Circuit Load

Safety Tip: Domestic lighting circuits in the UK are typically limited to **6 Amps**. This means the total wattage of all bulbs on one circuit should not exceed **1,380 Watts**. Switching to LED bulbs significantly reduces this load and allows for more fittings per circuit.

Illuminating Efficiency: UK Lighting Standards

The LED Revolution

The move to LED lighting has fundamentally changed how we design electrical circuits in UK homes. Where we once had to carefully manage 50W spotlights, we now have 5W fittings that provide better light with 90% less load.

Our **lighting load calculator** helps you verify that your circuit remains within the safe limits of its protective device (MCB), ensuring a safe and reliable installation.

Load Capacities (230V)

6 Amp Circuit1,380 Watts

10 Amp Circuit2,300 Watts

LED Average5W - 9W

Circuit Protection

In the UK, lighting circuits are traditionally wired using **1.0mm² or 1.5mm² Twin and Earth** cable and protected by a **6 Amp MCB (Miniature Circuit Breaker)**. The purpose of the breaker is to protect the cable from overheating in the event of an overload or a short circuit.

Even if your LED load is very small, the circuit must still be designed and tested to ensure it disconnects quickly enough during a fault to prevent fire or electric shock.

Inrush Current

While LED bulbs use very little power when running, they can have a high 'inrush current' when first turned on. If you have too many LED drivers on one circuit, the combined inrush can sometimes cause a Type B breaker to trip unnecessarily.

Fire Safety

When installing recessed downlights in a ceiling below a room or in a fire-rated ceiling, you must use 'Fire Rated' fittings. These contain an intumescent material that expands if a fire occurs, sealing the hole and preventing the spread of flames.

Pro Tip: Bathroom Zones

Lights installed in bathrooms must meet specific 'IP' (Ingress Protection) ratings depending on their proximity to water. In Zone 1 (above a bath or shower), fittings must be at least **IP44** or **IP65** and are often required to be SELV (Safety Extra Low Voltage).

Electrical & Lighting FAQ

Electrical Safety Disclaimer

This calculator is for estimation and planning only. Electrical installations in the UK must be carried out in accordance with BS 7671 (The IET Wiring Regulations) and should be designed, installed, and tested by a competent, registered electrician.