Perhaps while browsing our site for the perfect set of Christmas lights, you become a bit overwhelmed. You may wonder about types and bulb sizes, the difference between LED and incandescent, how many sets to buy, and whether you can plug them into your outlet safely. All these facets are important when it comes to buying the appropriate lights for your home and your particular use.
Types of Christmas Lights & Bulb Sizes
Confused about what kind of lights to buy? Consult our guide so you can choose the right size and shape that will live up to your holiday decorating dreams.
Mini lights are the most commonly used. The bulb shape resembles a candle with a pointed tip. They are generally 1/4 inch in diameter and 5/8 inch tall.
C6 lights are the smallest of the strawberry-shaped lights that many consider the “traditional Christmas bulb” shape. The bulbs are generally 3/4 inch in diameter and 1 1/8 inches tall.
C7 lights have the same strawberry shape as C6, but are slightly larger. They measure 1 inch in diameter and 1 1/2 inches tall. Their width gives them a rounded, bulbous look.
C9 lights have the same traditional strawberry shape as C6 and C7, but are slightly larger than C7. C9 lights measure 1 1/4 inches in diameter and 2 1/2 inches tall.
G Series are shaped like globes and come in a wide variety of sizes. The number after the G designates the maximum diameter of the bulb in eighths of an inch. To calculate the approximate diameter, you simply take the number after the G, divide it by 8, and round to the nearest inch. For example, G25 is a globe-shaped bulb approximately 3 inches in diameter, and G15 is a globe-shaped bulb that is almost 2 inches in diameter.
Commercial Grade Christmas Lights
If you’re decorating a business or commercial property, there are a few things you should keep in mind. They are made with a heavier gauge wire than residential lights; which means they can carry more power more efficiently over longer distances than regular sizes. The wire itself will be more durable as well.
You will need to hook up a power adapter when using commercial LED Christmas lights. Our power adapters are designed to connect at least one, and up to 125, commercial LED Christmas lights to a standard 120-volt power source. Power adapters have a standard two-pronged polarized Edison-style plug on one end, and a coaxial-style connector on the other end. Plug the two-prong end into your outlet, and the coaxial connector into your string of lights. The adapter provides strain relief between strings and prevents moisture from entering string connections.
Please note that only commercial LED Christmas lights need adapters. The power adapter is meant for use with items listed by “ANL” but is not required for other LED Christmas lights. Non-commercial-grade LEDs have a standard plug for your outlet.
Follow these recommendations when decorating with multiple strings of commercial LED Christmas lights:
- Max number of 25-bulb strings connected: 125
- Max number of 50-bulb strings connected: 62
- Max number of 100-bulb strings connected: 31
- Max number of LEDs (bulbs) connected: 3,125
Follow these recommendations when decorating with multiple strings of regular incandescent commercial Christmas lights:
- For mini bulbs of 50 to 100 per string, connect a maximum of three strings together.
- For larger bulbs such as C7, C9, etc., string together no more than 50 bulbs total.
Decorating Tips for Style and Safety
LED vs. Non-LED (Incandescent) Christmas Lights
Incandescent and LED are the two main types of Christmas lights. In the past, incandescent were the norm, consisting of glass bulbs with metallic filaments inside. LED Christmas lights, on the other hand, are Light Emitting Diodes that glow when they come in contact with an electrical current. Both types are acceptable for holiday lighting projects, but LED Christmas lights offer the following advantages:
- More energy efficient: LED Christmas lights use about 1/10th of the electricity consumed. Because the filaments in incandescent bulbs must be warmed in order to produce light, the bulbs waste a fair amount of energy generating heat instead of focusing on producing light. LED lights, on the other hand, do not have bulbs (only covers) and generate very little heat. For example, it takes only 4 watts to illuminate a 70-light LED string, but it takes 4-5 watts per bulb to illuminate a string of C7 incandescent lights.
- Safer: LED lights generate less heat, thus reducing the risk of fire.
- Longer life: LED lights last on average 10 times longer than standard incandescent lights, as they do not have filaments, which is the metallic part of incandescent bulbs that burns out or breaks easily.
- More durable: Because LED Christmas lights are made with hard plastic instead of glass, they are much more difficult to break. Glass-bulb incandescent lights break more easily. The colored layer of translucent paint on incandescent bulbs is also prone to fading and flaking when exposed to weather.
- Brighter colors: LED Christmas lights emit a brighter and more distinct color than their incandescent counterparts. Incandescent lights generally emit subtler, yellow-tinted colors, which can sometimes have a faded appearance.
Although LED has many advantages over conventional incandescent, LED lights also come with a higher price tag. All decorators must weigh the cost against the benefits to decide whether it’s worth it for their particular use. Remember, though, that you’ll be saving money in energy consumption costs by using LEDs because they require less electricity. They’re also safer, longer-lasting, and emit more intense colors.
While shopping for LED light sets, you might also come across Wide Angle LED lights. These miniature lights have a wide angle lens that diffuses light outward instead of focusing it at the tip of a bulb. Because of their ability to spread light, they are another option when striving for a brighter effect than traditional mini lights can provide.
How Many Christmas Lights Do I Need?
A great rule of thumb to remember is you should use approximately 100-150 mini Christmas lights per foot of tree. The 100-light recommendation will allow more room for ornaments and foliage to be seen, but the 150 recommendation will create a stronger twinkling effect. Slender trees will light up just fine with 100 lights per foot, but you will want to use 150 Christmas lights per foot for a tree with thick, full foliage. Here’s a light count guide for quick reference:
|6||600 – 900|
|7||700 – 1050|
|8||800 – 1200|
|9||900 – 1350|
|10||1000 – 1500|
Christmas Light Installation Tips
Decorating with Christmas lights can be a complicated project. With so many strings of lights, different kinds of plugs, extension cords, and power concerns, it’s easy to get overwhelmed. Here are a few tips to simplify your decorating process and keep you safe this year:
Hang them lit. Remember to plug your Christmas lights into the outlet before arranging them on the tree. This allows you to discover any loose bulbs or technical problems before the lights are on the tree or the house. It will also help you distribute the lighting evenly.
Connect only three sets. When connecting incandescent or LED Christmas lights end-to-end, do not exceed three sets.
Prevent surges. We recommend that light sets be plugged into a surge protector light bar to deter overload.
Separate by bulb count. Do not connect strings of different numbers of lights. When connecting strings of Christmas lights, you must separate by bulb count. Keep 100-light strings with 100-light strings, 50-light strings with 50-light strings, and so on for any number of lights. If you connect a 100-light set with a 50-light set, the 50-light set will burn out prematurely. The same is true with novelty light sets or tree toppers: if they don’t match the bulb count, then plug them into their own outlet on an extension cord to prevent burnout.
Don’t overload extension cords. A standard 9-foot-long extension cord with a three-plug receptacle will handle three light sets per plug receptacle: two on the front, and one on the back. Be sure to separate light sets by bulb count. You can have multiple bulb counts on the same extension cord, but you can’t plug them into the same plug receptacle outlet. For example, one plug receptacle could have three 100-light sets, the other plug receptacle could have three 50-light sets, and the third plug receptacle could have three 35-light sets.
How Many Amps Do Christmas Lights Use?
Watts and Amps
Pay attention to watts and amps when decorating your home with Christmas lights. The first thing to note is that the wattage of an incandescent bulb varies by size and by the length of the string. Although you can connect up to three sets of Christmas lights end-to-end, you still have to consider the total load that will be drawn from your outlet. A standard outlet can support only 16 amps. Often this exterior outlet is on the same circuit as the room on the other side of the wall. That means you have to add up the amps you’re already using inside the room to determine how many amps you have left for your exterior Christmas lights. You can calculate the number of amps you’ll need for your lights using this equation:
(Number of feet x Number of watts) / 125 volts = Number of amps
For example, incandescent C7 lights typically require about 5 watts per bulb. If you have a string measuring 200 feet, multiply 200 feet by 5 watts to get the total number of watts needed, which is 1000 watts. Then divide the 1000 watts by 125 volts to get a total of 8 amps. This string of lights will pull a total of 8 amps. Check if your plug has 8 amps to spare. If it does, you can plug your lights in there.
For mini incandescent lights, you can use the following approximations to determine amps:
- Light strings with 35 or 50 lights: 0.2 amps
- Light strings with 100 lights: 0.4 amps
Troubleshooting for Finicky Lights
If your LED or incandescent Christmas lights are not working, try these troubleshooting tips to find the source of the problem.
Got enough power? Make sure all circuits are on and all plugs are plugged into power sources that can handle the load.
Check the fuse. If your plug or light set has a fuse, check to see if the filament in the fuse is broken. If it is, replace it.
Spread plug prongs. Sometimes plug prongs don’t make full contact with the circuit. Gently pry the prongs slightly outward to ensure circuit contact.
Brighter than usual? If your incandescent lights seem brighter than usual, it’s likely that multiple lights have burned out. Find and replace the defective bulb(s).
Test with a tester. This method is particularly useful when testing incandescent mini light sets. Plug one light set into the plug outlet on the light tester. Push the test button on the tester. Any defective bulbs will make a buzzing sound. Note the bulbs that buzz and remove and replace all of them. If your light set has more than 50 lights, it might be easier to take each bulb out one at a time, plug it into the tester, and see if it’s defective. Continue until you find the defective light.
For successful replacement of a defective incandescent bulb, please follow these guidelines:
Unplug the lights first. Always unplug the light set before replacing a new bulb. If you don’t, you’ll have a current surge, which will burn out the new bulb.
Don’t mix and match. Just like strings of lights, don’t replace a bulb on a 35-light string with a bulb designed for a 50-light string. Bulbs for 35-light strings use 3.5 volts, but bulbs for 50-light strings use 2.5 volts. If you use the wrong voltage on a single bulb, then your light set will not work properly.
Stick to the same brand. Not all light sets and replacement bulbs are designed the same way. Use replacement bulbs from the same manufacturer that created your light set to ensure proper fit and function.