LED Wattage Calculator
Calculate total wattage required for your LED lighting system based on desired lumens, number of fixtures, and LED efficiency.
List of the Top 10 Best LED Bulb:
How to Calculate LED Wattage
Understanding wattage requirements is essential when designing energy-efficient lighting systems using LED technology. While traditional bulbs are selected by wattage, LED lighting is chosen by lumens — the amount of visible light emitted. Our LED Wattage Calculator helps you reverse-engineer the required wattage by knowing how many lumens you need and how efficient your LED fixtures are.
Basic Formula
Total System Wattage = Wattage per Fixture × Number of Fixtures
Example
If you need 10,000 lumens and your LEDs are 100 lumens/watt, the total wattage is:
- 10,000 ÷ 100 = 100W total
- Divided among 10 fixtures = 10W per fixture
What is Lumens per Watt?
Lumens per watt (lm/W) is a measure of LED efficiency — how much light you get per unit of electricity. The higher this number, the more efficient the bulb or fixture.
Typical LED Efficiencies
- Standard LED bulb: 80–110 lm/W
- High-performance LED panels: 120–150 lm/W
- Industrial high bays: 140–200+ lm/W
Why This Matters
- Helps size your transformer or power supply
- Enables accurate energy cost estimates
- Ensures proper fixture selection without under- or over-lighting
- Ensures circuit load doesn't exceed limits
Energy Efficiency Tips
- Use LEDs with higher lumens per watt to reduce electricity usage
- Install occupancy or motion sensors to limit usage time
- Use dimmable drivers or control systems to match lighting to task
Comparing LEDs to Traditional Bulbs
| Light Type | Lumens | Wattage | Efficiency (lm/W) |
|---|---|---|---|
| Incandescent 60W | 800 | 60W | ~13 lm/W |
| Compact Fluorescent (CFL) | 800 | 15W | ~53 lm/W |
| LED | 800 | 8–10W | 80–100+ lm/W |
Frequently Asked Questions
How many watts is 800 lumens in LED?
If your LED is 100 lm/W, then 800 ÷ 100 = 8 watts.
Can I replace a 60W bulb with a 10W LED?
Yes, as long as the LED outputs 800 lumens or more — it provides the same brightness using less power.
Do LED wattage ratings matter?
Yes. Total system wattage determines your power draw, electrical load, and energy usage.
What’s a good efficiency for commercial LEDs?
Modern commercial-grade LEDs should offer at least 120 lm/W, with high-efficiency models exceeding 150 lm/W.
How do I size my power supply for LEDs?
Use this calculator to determine total watts needed. Then choose a power supply with 10–20% headroom above that.
Does dimming affect wattage?
Yes, dimming reduces wattage consumption in real-time, though rated wattage stays the same.