What Are Lumens?

  • Lumens (lm) measure the total amount of visible light a source emits.

  • Unlike watts, which tell you how much power a lamp consumes, lumens directly indicate brightness.

  • For street lights, lumens are critical because they determine how much of the road, parking lot, or pedestrian area will be illuminated.

👉 Example:

  • A 100W LED street light can produce ~12,000–15,000 lumens.

  • A 250W sodium lamp produces about the same lumens but consumes more than double the energy.

How Many Lumens Do Street Lights Need?

The lumen requirement depends on application, road type, pole height, and safety standards. Here’s a guideline:

Application / Road Type Typical Pole Height Recommended Lumens
Small pathways / alleys 3–4 m 1,500–3,000 lm
Residential streets 5–6 m 3,000–6,000 lm
Urban streets / small roads 6–8 m 6,000–12,000 lm
Main roads / collectors 8–10 m 12,000–18,000 lm
Highways / expressways 10–12 m 18,000–30,000 lm
Large parking lots / airports 12–15 m+ 30,000–50,000 lm

Lumens vs. Lux in Street Lighting

  • Lumens = total light output from a fixture.

  • Lux (lx) = light that actually reaches a surface (lumens per square meter).

⚡ Example:

  • A 20,000 lumen street light on a 12 m pole might deliver ~15 lux on the road surface.

  • Lux requirements are set by standards (e.g., EN 13201 in Europe, IESNA in the US).

Typical lux levels:

  • Residential roads: 5–10 lux

  • Collector roads: 10–20 lux

  • Highways: 20–30 lux

LED Street Light Lumens Efficiency

Modern LED street lights achieve 120–160 lumens per watt (lm/W), meaning:

  • 50W LED → ~6,000–8,000 lm

  • 100W LED → ~12,000–15,000 lm

  • 150W LED → ~18,000–22,000 lm

  • 200W LED → ~24,000–30,000 lm

This efficiency is why a 100W LED can replace a 250W sodium lamp while providing equal or better brightness.

Factors Affecting Lumen Needs

  1. Pole Height – Higher poles require more lumens to cover the same lux level at ground.

  2. Pole Spacing – Wider spacing demands higher lumen output to avoid dark spots.

  3. Optical Design – Good lenses and reflectors ensure light is distributed evenly, reducing wasted lumens.

  4. Road Width & Traffic – Wider, busier roads need higher lumen fixtures for safety.

  5. Environment – Foggy or dusty areas may need stronger illumination.

Street Light Lumens Equivalency

Here’s a quick conversion chart:

Traditional Lamp Typical Lumens Equivalent LED Lumens LED Wattage
100W HPS ~9,500 lm 6,000–8,000 lm 40–60W
250W HPS ~26,000 lm 12,000–15,000 lm 100W
400W HPS ~50,000 lm 18,000–25,000 lm 150–200W
1000W MH ~110,000 lm 30,000–50,000 lm 300–400W

Why Lumens Matter More Than Watts

In the past, people judged brightness by watts (e.g., “a 100W bulb is brighter than a 60W bulb”).
With LEDs, wattage only shows power consumption. A more efficient LED can give higher lumens with less wattage.

👉 Always check the lumens rating and not just the wattage when choosing a street light.

Conclusion

Street light lumens are the true measure of brightness and the most important factor for road safety, urban comfort, and energy efficiency. By choosing the correct lumen output based on road type, pole height, and lux standards, municipalities and businesses can:

  • Ensure safety for drivers and pedestrians

  • Save 60–70% energy with LEDs

  • Reduce maintenance costs

  • Improve urban aesthetics and sustainability

When selecting a street light, always balance lumens, optics, and application needs — not just wattage.