Lighting basics
Lumens vs watts: how to compare LED lights properly
Watts tell you what a light consumes, lumens tell you what it delivers. Learn how efficacy (lm/W) separates a good LED from a cheap one, with replacement tables for HPSV, metal halide and CFL.
By Hi-Looms Technologies engineering team · Updated 12 October 2026 · 2 min read
Watts measure consumption, lumens measure light
With incandescent and sodium lamps everyone shopped by wattage because every lamp of a type produced about the same light. LEDs broke that rule. A 50 W fixture with quality chips and a well-designed driver can give 6,500 lm; a bargain 50 W fixture may give 4,000 lm and lose a third of it within a year.
Luminous efficacy (lumens per watt) is the number to compare. Today's good industrial LEDs run at 110–150 lm/W at the fixture level, after driver and optic losses.
Replacement guide
| Old lamp | Typical lumens | LED replacement |
|---|---|---|
| 60 W incandescent | 800 lm | 7–9 W LED bulb |
| 20 W CFL | 1,200 lm | 10–12 W LED bulb |
| 36 W fluorescent tube | 2,500 lm | 18–20 W LED batten or panel |
| 150 W HPSV street light | 12,000 lm (lamp) | 50–60 W LED street light |
| 250 W HPSV street light | 25,000 lm (lamp) | 100 W LED street light |
| 250 W metal halide highbay | 20,000 lm (lamp) | 100–120 W LED highbay |
| 400 W metal halide highbay | 32,000 lm (lamp) | 150–200 W LED highbay |
| 1,000 W metal halide flood | 90,000 lm (lamp) | 300–400 W LED flood |
LED replacements look small because old lamps lost 30–50% of their light inside the fixture and through the ballast, and depreciated quickly. LEDs are directional, so more of the rated lumens reach the task.
What else changes the result
- Colour temperature: 6500 K daylight fixtures look brighter than 3000 K warm white at the same lumens; most Indian outdoor projects specify 5700–6500 K, offices 4000 K.
- Optics: a street light with a Type II distribution puts light on the road rather than into the sky, so 10,000 lm on the road beats 12,000 lm scattered everywhere.
- Driver quality: constant-current drivers with power factor above 0.9 and surge protection of 4–10 kV keep output stable on Indian grids.
- Thermal design: a die-cast aluminium housing keeps LED junction temperature low, which is what makes a 50,000-hour life claim real.
Every product page on this site lists lumens, efficacy and CCT where the factory has published photometric data, and our calculator sizes projects on lumens rather than watts.
Frequently asked questions
How many lumens is a 100 W LED street light?
At a typical 110–130 lm/W, a 100 W LED street light delivers 11,000 to 13,000 lumens, which replaces a 250 W HPSV lamp.
Is a higher wattage LED always brighter?
No. Two 50 W fixtures can differ by 40% in output depending on the LED chips, driver current and optics. Compare lumens and lm/W, not watts.