If you’ve ever stood inside a motorhome on a rainy evening, fumbling for a light switch while squinting at dim, flickering bulbs that cast weird, unflattering shadows across your kitchenette, you know how much the right lighting can make or break a road trip. As someone who’s spent the last decade sourcing and supplying motorhome lights for customers all over North America and Europe, I’ve heard every lighting horror story imaginable. There’s the guy who installed too many 100-watt incandescents and blew his inverter mid-campground stay. There’s the family who bought tiny, clip-on bulbs that died an hour into a trip, leaving them fumbling for flashlights in the dark. Most of all, I’ve learned that choosing the right size of motorhome lights isn’t just about picking something that fits your ceiling or wall. It’s about matching the light to the space, the power system, and how you actually use your home on wheels. Motorhome Lights
Let’s start with the basics: what “size” even means when we talk about motorhome lights. For most people, the first thing that comes to mind is physical size—like, will this light fit into the existing cutout in my RV ceiling, or can I mount it on that empty wall above the dinette? But size also means lumen output, beam angle, and power draw—three numbers that matter way more than whether a light matches your throw pillows. I’ve seen people skip over lumen output and buy a light that’s the same shape as their old one, only to end up with a space that’s either too dark to read or so bright it gives them a headache after 10 minutes. Here’s how to break it down step by step, no confusing jargon required.
First, measure the space you’re lighting, and then match light size (physical and functional) to that square footage. This is the part I get asked about most, so let’s keep it simple: for every 50 to 75 square feet of living space in your motorhome, you need about 1,000 lumens of light total. Wait, let’s test that with a real example. A typical Class C motorhome has a main living area that’s around 12 feet long by 8 feet wide, or 96 square feet. That means you need roughly 1,200 to 1,920 lumens for that whole space. If you install four lights each rated at 500 lumens, that’s overkill—you’ll be squinting to see when you first turn them on, and then they’ll be way too bright once your eyes adjust. If you install two 500-lumen lights, that’s only 1,000 lumens, which is just enough to find your way around but not enough to read a book at the dinette or prep dinner at the counter. For that same 96-square-foot space, two 600-lumen lights work perfectly. They’re not too bright, they spread light evenly, and they give you enough visibility for daily tasks.
But here’s the catch: not all lights spread light the same way. That’s where beam angle comes in, which is another piece of “size” that trips people up. A narrow beam angle (20 to 30 degrees) is like a flashlight—it lights up a small, specific spot. That’s great for your outside awning light or a reading nook above your bed, but it’s terrible for a main living area, because you’ll end up with dark corners. A wide beam angle (90 to 120 degrees) spreads light across a whole space, so it’s ideal for kitchens, dinettes, and living areas. So when you’re calculating size, don’t just look at lumens—check the beam angle, too. A 600-lumen light with a 120-degree beam will cover more space evenly than a 800-lumen light with a 20-degree beam, and it’ll use less power to boot. I always tell customers to match beam angle to function: narrow for task-specific spots, wide for general living areas.
Physical size is next, and this is where most people start, which makes sense—you don’t want to buy a light that won’t fit your existing cutout or mount. First, check your current lights: if you’re replacing an old incandescent or fluorescent, measure the diameter of the cutout in your ceiling or wall. Most standard motorhome ceiling lights have a cutout between 6 and 8 inches, so a round LED light that’s 7 inches in diameter will fit perfectly. For recessed lights, the size is usually marked on the old trim or the base of the bulb—look for a number like “6-inch” or “4-inch,” which refers to the diameter of the opening. If you’re adding new lights, not replacing old ones, measure the space where you want to mount the light. If you have a small nook above your galley sink, a 4-inch round light will fit, but if you want to mount a light above a 4-foot dinette bench, a 12-inch oval light will cover more area evenly than two small round lights.
Here’s a pro tip I’ve picked up after years of working with motorhome owners: don’t just go by the size of the light you can physically fit. If you have a small cutout in a part of your motorhome that gets a lot of use, you can use a larger light with a slim profile. Many of the lights we supply are only 1.5 inches thick, so they fit into standard ceiling cutouts without sticking down too far—no bumping your head when you stand up from the dinette. I had a customer last year who had a tiny 6-inch cutout in her Class B van, and she thought she had to go with a small 5-inch light that only put out 300 lumens. She ended up installing a 6-inch slim LED light that put out 800 lumens, and it fit perfectly, no issues. The slim design is a game-changer for smaller motorhomes where headroom is tight.
Now, let’s talk about power, which is tied directly to light size and is the biggest mistake I see people make. Motorhomes run on 12-volt DC power, unlike your house’s 120-volt AC, so every light has a wattage that’s way lower than what you’d find in a home bulb. Old incandescent motorhome lights use 10 to 20 watts each, while LEDs use 2 to 5 watts for the same amount of light. But even LEDs, if they’re the wrong size, can drain your battery faster than you think. The rule here is simple: for every 100 amp-hours of battery capacity in your motorhome, you can run about 100 watts of lights for an hour before needing to recharge. If you have two 100-watt solar panels on your roof, that’s about 120 watts of power you can use during the day. So if you’re installing two 5-watt LED lights, that’s 10 watts total, which is nothing—you can run them for 10 hours and still have power left for your fridge and water pump. But if you install two 15-watt LED lights, that’s 30 watts total, and if you’re boondocking (camping off-grid) for a few days without solar, that adds up.
I had a customer last spring who bought a set of large, bright LED lights from a big-box store, thinking they were a steal. He installed them in his Class A motorhome, and within two days of boondocking, his batteries were dead. When he brought them to me, I checked the specs: each light was 20 watts, so four of them added up to 80 watts. His solar panels only put out 100 watts a day, so after running the lights for a few hours at night, he had no power left. The problem was he didn’t match the light size to his power system—he just picked the brightest light he could find. The right size of light isn’t just bright enough; it’s bright enough without draining your power. For off-grid motorhomes, I always recommend lights that are under 10 watts total for the main living area, with a few narrow-beam reading lights that are 3 to 5 watts each. That way, you have enough light without worrying about your battery dying mid-trip.
Another thing to consider is the type of motorhome you have, because that changes what size light works best. Class A motorhomes are the big ones, 30 to 40 feet long, with tons of living space. Their main living areas are huge, so you’ll need larger lights with wider beam angles—8 to 10 inch oval lights that put out 800 to 1,000 lumens each. Class C motorhomes are smaller, around 20 to 30 feet, with a main living area that’s compact, so 6 to 8 inch round lights that put out 500 to 700 lumens each work best. Class B van conversions are the smallest, under 20 feet, with limited headroom, so slim 4 to 6 inch round lights that are only 1 to 2 inches thick are ideal. I’ve also found that for bunk beds in towable travel trailers or Class Cs, tiny 3 inch clip-on lights that put out 150 to 200 lumens are perfect—they fit in the small space, and they’re bright enough for reading without taking up too much room.
Don’t forget about special areas, either. The galley kitchen is where you prep food, so you need a light that’s bright enough to see what you’re doing, but not so bright that it reflects off your stainless steel countertop. Under-cabinet lights are perfect here, and their size depends on how long your counter is. If you have a 4-foot counter, two 18-inch under-cabinet lights will cover it evenly, without dark spots near the ends. The bedroom is where you want softer light, so smaller lights with a warm color temperature (2700K to 3000K, which gives off a yellowish, homey glow) instead of bright white (5000K and up). A 5 inch round light with a warm 3000K color and a wide beam is perfect for a bedroom, because it’s not too harsh, and it’s bright enough to get ready in the morning without blinding you. The outside of your motorhome is another area—awning lights, entry lights, and backup lights. For awning lights, a narrow beam 10 inch light that puts out 1000 lumens works great, because it lights up the area right outside your door without shining in your neighbor’s RV. Entry lights need to be small, around 3 to 4 inches, because you don’t want something sticking out too far when you open your door.
I’ve learned over the years that the best way to choose the right size is to test before you buy, if you can. If you’re replacing old lights, take a photo of the current space and measure the cutout, then match that to the light specs. If you’re adding new lights, borrow a light from a friend or a local RV supply store that’s close to the size you’re considering, and hold it up to the space at night to see how it looks. Most good motorhome light suppliers will let you return lights if they don’t fit or don’t work, but that’s a hassle you can avoid by doing a little measuring and planning first.
Wait, one last common mistake: people buy lights that are too small because they’re afraid of wasting power, only to end up with a space that’s so dark it’s not usable. I had a customer last year who installed tiny 200-lumen lights in his Class C, and he emailed me a photo of him struggling to find his keys in the dark. He said he thought 200 lumens was enough, but he needed at least 500 lumens to feel comfortable. It’s better to calculate how much light you actually need for the space, not to skimp on size to save a few watts. Most modern LEDs are so efficient that a 600-lumen light only uses 5 watts, so the power difference between a small light and a large one is negligible. The old adage of “bigger is better” doesn’t apply here, but “right size for the space” does.
At the end of the day, choosing the right size of motorhome lights is about making your home on wheels feel comfortable and functional, without wasting power or money. It’s about measuring the space, matching beam angle to what you use it for, checking the cutout size, and making sure the power draw fits your battery and solar setup. I’ve been in the motorhome lighting business for long enough to know that the best road trips aren’t just about the destination—they’re about coming inside after a long day of driving and having a space that feels like home, lit just right. If you’re not sure what size works for your motorhome, feel free to reach out to our team for help—we’ve worked with thousands of motorhome owners, from first-time buyers to full-time RVers, and we can help you pick the perfect lights for your space. Whether you need slim lights for a Class B, bright lights for a Class A, or small reading lights for a bunk, we’ve got you covered.
Caravan Wall Lights References:
- RV Industry Association. (2022). RV Electrical System Best Practices.
- Illuminating Engineering Society. (2021). Lighting for Recreational Vehicles and Mobile Homes.
- National RV Dealers Association. (2023). Guide to RV Interior Lighting Selection and Installation.
- Energy Star. (2022). LED Lighting for Off-Grid and Recreational Applications.
- Recreational Vehicle Technical Association. (2021). RV Interior Space Planning and Lighting Specifications.
Foshan Nanhai Xingyuke Lighting Co., Ltd.
As one of the most professional motorhome lights manufacturers and suppliers in China, we also support customized service. If you’re going to buy advanced motorhome lights made in China, welcome to get free sample from our factory. For price consultation, contact us.
Address: 5th Floor, Yifeng Technology Park, Dawo Village, Danzao Town, Nanhai District, Foshan City, Guangdong Province, China
E-mail: york@nrylighting.com
WebSite: https://www.nrylighting.com/
