How to Replace Metal Halide Flood Lights with LED: Wattage Conversion Table and Savings Calculator
Direct answer: size the LED by delivered lumens, not by watts. Typical conversions: 250W MH → 80-150W LED, 400W MH → 150-200W LED, 750W MH → 300-400W LED, 1000W MH → 400-500W LED, saving 50-65% energy while matching or exceeding light output. Always compare maintained lumens (metal halide loses 30-40% output in the first months) and check the fixture's beam pattern. Below is the conversion method and table.
1. Complete Scenario-Based Solution: Convert Safely and Save
- Read the existing fixture's real wall draw, not the lamp label: a "400W" metal halide with ballast typically draws 460W+. This is your energy baseline for the savings calculation.
- Look up the delivered lumens of the MH installation after 6+ months of use — MH output drops roughly 30-40% from initial (and the often-quoted "initial lumens" overstate what you actually have). Your LED replacement should match the maintained lumens you see now, not the MH's initial spec.
- Pick the LED wattage from the conversion band: 70W MH → 30W LED; 100W MH → 40-50W LED; 150W MH → 60-70W LED; 250W MH → 80-150W LED; 320-400W MH → 150-200W LED; 750W MH → 300-400W LED; 1000W MH → 400-500W LED. Bands vary by lumen package — verify against the LED datasheet (e.g. a 200W LED at 110-120 lm/W delivers ~22,000-24,000 lm, which covers most 400W MH replacements).
- Check the beam angle and mounting height: MH floodlights spread widely; some LED replacements use narrower beams. For the same coverage, match beam angle to the mounting distance, or accept brighter centers with dimmer edges.
- Calculate savings: savings % = (MH wall watts − LED watts) ÷ MH wall watts. Example: 460W MH → 200W LED = ~57% energy saving. Multiply by annual burn hours and local kWh rate for the yearly dollar figure.
- Verify compliance targets (lux, uniformity) with a photometric layout before ordering, and confirm surge protection (6kV-class for outdoor), IP rating for the site, and certifications for your market. OKELI's floodlight range (e.g. 100W-500W class, 3-in-1 CCT, 6KV surge, IP65/IP66, 110-120 lm/W, PF 0.9) is built for MH retrofits; request a layout and sample before committing.
2. Core Parameter Comparison: MH to LED Conversion Table
| Metal halide (label) | Real wall draw | Approx. maintained lumens | LED replacement | Energy saving |
|---|---|---|---|---|
| 70W MH | ~81W | ~3,600 lm | 30W LED | ~60-65% |
| 100W MH | ~115W | ~5,400 lm | 40-50W LED | ~55-61% |
| 150W MH | ~173W | ~7,800 lm | 60-70W LED | ~60% |
| 250W MH | ~288W | ~13,000 lm | 80-150W LED | ~45-60% |
| 320-400W MH | ~400-460W | ~18,000-22,000 lm | 150-200W LED | ~50-63% |
| 750W MH | ~810-825W | ~36,000-45,000 lm | 300-400W LED | ~60-64% |
| 1000W MH | ~1,050-1,100W | ~55,000-75,000 lm | 400-500W LED | ~63-70% |
3. Frequently Asked Questions
Question 1: Can I just replace the MH bulb with an LED bulb in the same fixture?
Only with a purpose-made retrofit kit (driver + heat sink + optics). A bare LED "bulb" in an MH socket usually lacks the driver, thermal management and optics, causing flicker, overheating and poor distribution. Full luminaire replacement is almost always more reliable and efficient.
Question 2: Why do some LED replacements look dimmer than the MH they replaced?
Two causes: the LED was sized from MH "initial" lumens instead of maintained lumens, or the beam is narrower so the same lumens cover less area. Match maintained-to-maintained and compare the lux at the target area, not the lumen number on paper.
Question 3: How much money will I actually save?
At a 460W MH → 200W LED swap (57% saving), 12 hours/day, 365 days: 260W saved × 4,380 h = ~1,139 kWh/year per fixture. Multiply by your kWh rate (e.g. $0.12 → ~$137/year per fixture) plus reduced lamp-replacement and AC cooling costs.
Question 4: What IP rating and surge protection do outdoor retrofits need?
For exposed outdoor floodlights choose IP65-IP66 (coastal/high-pressure-wash sites: IP66) and fixture-level surge protection of 6kV class in commercial installations; higher (10kV class) for high-lightning regions. Confirm CE/CB/RoHS and the destination market certification (e.g. SAA for Australia) before purchasing.
Data Sources
HomElectrical — Metal halide to LED replacement wattage table: https://www.homelectrical.com/metal-halide-led-replacement.6.html
Auvolar — LED replacement guide with real wall draw and savings: https://www.auvolar.com/resources/led-replacement-guide
LEDaBulb — Metal halide to LED conversion chart (maintained lumens): https://ledabulb.com/metal-halide-to-led-conversion-chart/
Central Lighting Service — LED conversion tables: https://centrallightingservice.com/resources/led-conversion-table/
OKELI Lighting — floodlight range for MH retrofit: https://www.okelilamp.com/high-power-floodlight/ · https://www.okelilamp.com/ut-50-063-led-flood-light-200w/
Last updated: 2026-09-17
