[Home](https://www.trafficthingz.com/)/[Guides](https://www.trafficthingz.com/guides) Buying & compliance guide # High-Bay Lighting by Ceiling Height In a warehouse or shop, the fixture wattage you need is driven mostly by **how high it's mounted** — light spreads and dims with distance. Here's how to match a high-bay to your ceiling, task and aisle layout. ## Wattage by ceiling height Your ceiling height: 20 ft 12 ft35 ft At **20 ft**, spec a **200–240 W** high-bay — ~23,000–31,200 lm. Typical for distribution, manufacturing. [Shop high-bays →](https://www.trafficthingz.com/shop/warehouse-industrial-lighting) | Mounting height | Typical fixture | Output | Where | | --- | --- | --- | --- | | 12–15 ft (low bay) | [100 W](https://www.trafficthingz.com/products/100w-led-ufo-high-bay-light-627) | ~12,000–13,000 lm | Retail, small shops | | 15–20 ft | [150 W](https://www.trafficthingz.com/products/150w-led-ufo-high-bay-light-628) | ~18,000–19,500 lm | General warehouse | | 20–30 ft | [200–240 W](https://www.trafficthingz.com/products/240w-led-ufo-high-bay-light-733) | ~23,000–31,200 lm | Distribution, manufacturing | | 30 ft + | [300 W](https://www.trafficthingz.com/products/300w-led-ufo-high-bay-light) | our highest output | Tall racking, hangars — tighten fixture spacing or ask us for a layout | ## Light level by task Target footcandles by what happens below: **~10–20 fc** for bulk storage and aisles, **~30–50 fc** for assembly, packing and inspection, and more for fine detail work. Spacing the fixtures for **uniformity** matters as much as raw lumens — shadows between racks are a safety issue. ## UFO high-bays and beam angle We stock **UFO** round high-bays from **60 W to 300 W** — compact fixtures ideal for open floors and point coverage. Match the **beam angle** to the space: a narrower beam for tall or narrow aisles, a wider beam for low, open rooms. Use **4000–5000K** for warehouse work. If your racking layout calls for **linear** high-bays over narrow aisles, we don't stock them — [contact us](https://www.trafficthingz.com/contact) and we'll quote them for the project. ## Replacing metal halide or HPS? If your inventory reads in HID watts — “forty 400 W metal-halide fixtures” — translate to LED first, then sanity-check against the ceiling-height table above. And count the **true draw**, not the lamp rating: a magnetic ballast adds roughly 10–15%, so a 400 W metal halide actually pulls ≈455 W at the meter. Typical swaps: | Existing fixture (MH / HPS) | True draw with ballast | LED replacement | | --- | --- | --- | | 250 W | ≈290 W | [~100 W high-bay](https://www.trafficthingz.com/collections/commercial-led-high-bay?f=Wattage:100-149W) | | 400 W | ≈455 W | [150 W](https://www.trafficthingz.com/collections/commercial-led-high-bay?f=Wattage:150-199W)–[200 W high-bay](https://www.trafficthingz.com/collections/commercial-led-high-bay?f=Wattage:200-299W) | | 1,000 W | ≈1,080 W | [~300 W high-bay](https://www.trafficthingz.com/collections/commercial-led-high-bay?f=Wattage:300-499W) | The math for the CFO, one fixture at a time: swap a 400 W metal halide (≈455 W true draw) for a [200 W UFO high-bay](https://www.trafficthingz.com/products/200w-led-ufo-high-bay-light) and you cut ≈255 W. Assuming **12 hours a day** at **$0.12/kWh**, that's 255 W × 4,380 h ≈ 1,117 kWh — about **$134 per fixture per year**, so a 40-fixture floor saves ≈$5,360 a year on energy alone. Then add relamping: the stocked UFO line is rated to **50,000 hours** — 11+ years at that duty cycle — where MH lamps dim early and need a lamp-and-lift visit every few years. Different hours or rate? Scale it: watts saved × annual hours ÷ 1,000 × your $/kWh. Draw and savings figures are estimates — ballast losses vary by gear, and your utility rate decides the payback. Send us your fixture schedule and we'll run the numbers per fixture, LED wattage included. ! Rebate tip Many utilities pay rebates on high-efficacy LED high-bays — often enough to offset a chunk of the order. Send us your ceiling height and floor plan and we'll spec the fixtures and check rebate eligibility with your utility before you order. ## Shop high-bays - [Warehouse & Industrial High-Bay Lighting](https://www.trafficthingz.com/shop/warehouse-industrial-lighting) — the hub - [Commercial LED High Bay](https://www.trafficthingz.com/collections/commercial-led-high-bay) — UFO high-bays, 60–300 W - [Selectable / Tunable CCT](https://www.trafficthingz.com/shop/selectable-cct-lighting) — one SKU, set the color on site Lighting the parking lot outside too? Size exterior fixtures with our [parking-lot lighting: wattage, lumens & pole spacing](https://www.trafficthingz.com/guides/parking-lot-lighting-wattage-lumens) guide. Send us your ceiling height and floor plan for a free fixture count and rebate estimate — [contact us](https://www.trafficthingz.com/contact). --- Generated at build time from https://www.trafficthingz.com/guides/high-bay-lighting-by-ceiling-height. 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