How Many Watts Do Outdoor String Lights Use Find Out Now

Outdoor string lights typically use 5 to 20 watts per bulb, with total consumption depending on bulb type, length, and usage. LED options are far more energy-efficient, using up to 80% less power than incandescent or halogen bulbs—making them ideal for cost-effective, eco-friendly outdoor lighting.

Key Takeaways

• Wattage varies: LED strings use 1-5 watts per bulb, incandescents use 5-15 watts.
• Check labels: Always verify wattage on packaging for accurate energy estimates.
• LEDs save energy: Choose LEDs to cut power use by up to 80%.
• Total wattage matters: Multiply bulb wattage by count to size circuits safely.
• Smart choices count: Use timers or dimmers to reduce unnecessary power draw.

How Many Watts Do Outdoor String Lights Use? Find Out Now

Imagine this: it’s a warm summer evening, the sun has just dipped below the horizon, and your backyard transforms into a cozy, glowing haven thanks to your outdoor string lights. Whether you’re hosting a barbecue, enjoying a quiet night with a book, or creating a romantic atmosphere, string lights can elevate any outdoor space. But have you ever wondered how many watts outdoor string lights use? It’s a question that often pops up, especially when you’re trying to balance ambiance, energy efficiency, and electricity bills.

Outdoor string lights come in all shapes, sizes, and technologies—incandescent, LED, solar-powered, and more—and each has a different power consumption profile. Knowing the wattage helps you plan your setup, avoid overloading circuits, and even choose eco-friendly options. Whether you’re a first-time buyer or a seasoned decorator, understanding wattage is key to making informed decisions. In this post, we’ll break down everything you need to know about watt usage in outdoor string lights, from the types available to practical tips for saving energy—all while keeping your space beautifully lit.

Understanding Wattage: The Basics of Power Consumption

What Does “Watt” Actually Mean?

Before diving into specific numbers, let’s get clear on what a watt is. A watt (W) is a unit of power that measures how much electrical energy a device uses per second. In simpler terms, it tells you how “hard” a light is working to produce brightness. The higher the wattage, the more electricity it consumes—and the more it costs to run.

For example, a 60-watt incandescent bulb uses 60 watts of power every hour it’s on. But here’s the twist: brightness isn’t always tied directly to wattage, especially with newer lighting technologies. That’s why we now use lumens to measure light output (brightness), while watts measure energy use.

Why Wattage Matters for Outdoor String Lights

When setting up outdoor lights, wattage affects three main things:

• Energy costs: Higher wattage = higher electricity bills, especially if you run lights for hours.
• Circuit capacity: Your outdoor electrical outlets and extension cords have limits. Too many high-wattage lights can trip breakers or cause fires.
• Heat and safety: Incandescent lights get hot. High wattage over long periods can be a fire hazard, especially near dry plants or flammable materials.

For instance, I once set up 10 strands of 100-watt incandescent string lights across my patio. They looked amazing—but within 30 minutes, the circuit breaker tripped. After switching to LED lights, I got the same glow with just 15 watts per strand. That’s the power of understanding wattage!

Types of Outdoor String Lights and Their Wattage

Incandescent String Lights: Classic but Power-Hungry

These are the traditional bulbs you might remember from holidays or old cafes. They have a warm, nostalgic glow and are often used for festive decor. But here’s the catch: they use a lot of watts.

• A typical incandescent bulb in a string light uses 5 to 15 watts per bulb.
• Standard 10-light strings: 50 to 150 watts total.
• Longer strands (25+ bulbs): 125 to 375 watts.

Let’s say you have a 25-foot strand with 25 bulbs, each using 10 watts. That’s 250 watts per strand. Run it for 5 hours a night, and you’re using 1.25 kilowatt-hours (kWh) daily. At $0.15 per kWh, that’s about $5.60 per month—just for one strand!

Tip: If you love the warm look of incandescent lights but want to save energy, consider using them only for special occasions or in shorter runs.

LED String Lights: Energy-Efficient and Long-Lasting

LEDs are the go-to choice for most outdoor setups today—and for good reason. They use a fraction of the power of incandescent bulbs while offering the same (or better) brightness.

• LED bulbs use 0.1 to 1.5 watts per bulb.
• Standard 10-light string: 1 to 15 watts total.
• Longer 50-light strand: 5 to 75 watts total.

For example, a 50-bulb LED string using 0.5 watts per bulb uses just 25 watts total—that’s 1/10th the power of a similar incandescent strand. Run it for 5 hours? Only 0.125 kWh per day, or about $0.56 per month. Huge savings!

LEDs also last longer (25,000–50,000 hours vs. 1,000 for incandescent), don’t get hot, and are available in warm white, cool white, multicolor, and even color-changing options.

Solar-Powered String Lights: Zero Grid Wattage

These lights run on sunlight, so they use zero watts from your home’s electrical system. The solar panel charges a battery during the day, and the lights turn on automatically at dusk.

• Power draw from the grid: 0 watts.
• Battery capacity: Usually 600–2000 mAh, powering 20–50 LED bulbs.
• Runtime: 6–12 hours, depending on sunlight and battery size.

While solar lights don’t add to your electricity bill, their performance depends on weather and placement. I use solar lights along my garden path—they’re perfect for soft, ambient lighting but aren’t bright enough for large patios or events.

Tip: Clean the solar panel monthly and place it in direct sunlight for best results.

Smart and RGB Color-Changing Lights

These are LED-based but often use slightly more power due to color mixing and smart features (Wi-Fi, Bluetooth, app control).

• Per-bulb wattage: 0.2 to 2 watts (higher when showing bright red or white).
• 50-light strand: 10 to 100 watts total.
• Smart features may add 1–2 watts of “standby” power when not in use.

For example, a 50-bulb smart RGB string using 1.5 watts per bulb in white mode uses 75 watts. But when set to a soft pink or blue, it might drop to 50 watts. The flexibility is great, but it’s worth checking the specs.

How to Calculate Total Wattage for Your Setup

Add Up the Watts Per Strand

Calculating total wattage is simple: add the wattage of each string light you plan to use. Always check the packaging or product description for the total wattage per strand. If it only lists watts per bulb, multiply by the number of bulbs.

Example: You want to hang 4 strands of LED lights. Each has 20 bulbs using 0.3 watts per bulb.

• Per strand: 20 x 0.3 = 6 watts
• Total for 4 strands: 4 x 6 = 24 watts

That’s a tiny load—perfect for long-term use!

Check Your Outdoor Circuit Limits

Outdoor outlets are usually on 15-amp circuits. In the U.S., that means a maximum of:

• 1,800 watts (15 amps x 120 volts)

But it’s best to stay under 80% of that—so 1,440 watts max—to avoid tripping the breaker.

Example: You have 10 strands of 100-watt incandescent lights. Total: 1,000 watts. That’s under 1,440, so it should work—but if you plug in a space heater or power tool, you might overload the circuit.

Tip: Use a wattage meter (like a Kill-A-Watt) to measure real-time power use. It’s a small investment that can prevent big problems.

Factor in Extension Cords and Splitters

Extension cords and power strips have their own wattage limits. A typical 16-gauge outdoor extension cord can handle up to 1,625 watts. But if it’s long (50+ feet) or low quality, it may overheat under heavy loads.

Always:

• Use outdoor-rated cords and splitters.
• Check the wattage rating on the cord (look for “10A” or “15A”).
• Avoid daisy-chaining more than 2–3 cords.

I learned this the hard way when a cheap splitter melted after running 800 watts for an hour. Now I only use heavy-duty cords and keep total load under 1,200 watts.

Energy-Saving Tips to Reduce Watt Usage

Switch to LED (Even If It’s a Gradual Move)

If you’re still using incandescent string lights, switch to LED. You’ll save up to 90% on power use and cut maintenance (no more replacing burnt-out bulbs every season).

You don’t have to replace everything at once. Start with one strand, then add more LEDs over time. I replaced my patio lights strand by strand—within a year, I saved over $80 in electricity.

Use Timers or Smart Plugs

Even low-wattage lights add up if left on all night. A simple solution? Use a timer.

• Mechanical timer: Costs $10–$20, turns lights on/off at set times.
• Smart plug: Lets you control lights from your phone or voice assistant (e.g., “Hey Google, turn off the patio lights”).

I use a smart plug for my backyard lights. They turn on at sunset and off at 11 PM—no wasted energy.

Choose Lower-Brightness Settings (For Smart Lights)

If you have RGB or smart string lights, use the app to dim them. A 50% brightness setting can cut wattage in half. For ambient lighting, you rarely need full brightness.

For example, a 50-watt RGB strand at 50% brightness uses just 25 watts—same as a basic LED strand.

Group Lights Strategically

Instead of lighting every inch of your yard, focus on key areas:

• Patio or dining table
• Walkways (use solar path lights)
• Under trees or pergolas

This “zoned” lighting reduces total wattage while enhancing ambiance. I used to light my entire backyard—now I focus on the seating area and save 60% on power.

Clean and Maintain Your Lights

Dust, dirt, and moisture can make bulbs less efficient. Clean LED lenses monthly with a soft cloth. Check for loose connections or frayed wires—these can increase resistance and power use.

Solar lights need extra care: clean the solar panel and replace batteries every 1–2 years.

Real-World Wattage Comparison Table

To help you compare, here’s a quick look at common outdoor string light types and their average wattage per 10-bulb strand:

Type	Watts per Bulb	Total Watts (10 Bulbs)	Monthly Cost (5 hrs/day)	Lifespan
Incandescent	5–15 W	50–150 W	$1.12–$3.38	1,000 hrs
LED (Standard)	0.1–1 W	1–10 W	$0.02–$0.23	25,000–50,000 hrs
LED (RGB/Smart)	0.2–2 W	2–20 W	$0.05–$0.45	25,000 hrs
Solar-Powered	0 W (grid)	0 W (grid)	$0	2,000–5,000 hrs (battery)

Note: Monthly cost based on $0.15 per kWh. Solar costs assume no grid use.

This table shows why LEDs are the smart choice for most users. Even the highest-end smart LEDs cost less than $0.50 per month to run—less than a cup of coffee!

Final Thoughts: Balancing Beauty and Efficiency

Outdoor string lights can turn any space into a magical retreat—but they shouldn’t drain your wallet or your circuit breaker. Knowing how many watts outdoor string lights use puts you in control. Whether you’re going for a cozy glow or a vibrant party vibe, there’s a lighting option that fits your needs and budget.

Start by choosing LED or solar lights for everyday use. They’re efficient, safe, and long-lasting. Use timers and smart controls to avoid wasting energy. And if you love the look of incandescent lights, save them for special occasions—or swap them out for LED “vintage” bulbs that mimic the warm glow without the high wattage.

Remember, it’s not just about saving money. It’s about enjoying your outdoor space without stress. I’ve spent countless evenings under my string lights—reading, grilling, laughing with friends. And now, I do it with peace of mind, knowing my lights are efficient, safe, and beautiful.

So go ahead—hang those lights, press that timer, and enjoy the glow. With the right wattage knowledge, your backyard can shine—brightly and affordably—for years to come.

Frequently Asked Questions

How many watts do outdoor string lights typically use?

Most outdoor string lights use between 5 to 20 watts per bulb, depending on the bulb type (LED vs. incandescent) and length of the strand. LED options are far more energy-efficient, often using 80% less power than traditional incandescent bulbs.

Are LED outdoor string lights more energy-efficient than incandescent?

Yes, LED outdoor string lights use significantly fewer watts—usually 1-5 watts per bulb—compared to 10-20 watts for incandescent bulbs. This makes LEDs a cost-effective and eco-friendly choice for long-term outdoor lighting.

How many watts do solar-powered outdoor string lights use?

Solar-powered outdoor string lights typically use 1-5 watts per bulb since they rely on stored solar energy. Their low wattage makes them ideal for energy-conscious users, though brightness may vary based on sunlight exposure.

Can I connect multiple outdoor string lights without overloading the circuit?

Yes, but check the total wattage: most outdoor circuits handle 15-20 amps (1,800-2,400 watts). For example, 10 strands of 50-watt LED lights use only 500 watts total, leaving room for other devices.

Do outdoor string lights with more bulbs use more watts?

Generally, yes—more bulbs mean higher total wattage. However, LED string lights with 50 bulbs may use only 25 watts total, while incandescent equivalents could use 100+ watts for the same length.

How do I calculate the wattage of my outdoor string lights?

Check the product label or manual for watts per bulb, then multiply by the number of bulbs. For example, 20 LED bulbs at 2 watts each use 40 watts total—a key detail for managing energy use.