How to Know the Pin Size of Laptop Charger

Buying a replacement charger? You need to match the pin size exactly or risk damaging your laptop.

Laptop charger pin sizes are measured in millimeters using two dimensions: outer diameter (OD) and inner diameter (ID). For example, 5.5/2.5mm means 5.5mm outer diameter and 2.5mm inner diameter.

Understanding Laptop Charger Pin Size

Pin sizes are measured in millimeters. The format is: Outer Diameter / Inner Diameter.

For example, a pin listed as 5.5/2.5mm has a 5.5mm outer metal ring and a 2.5mm inner metal ring. Both must match your laptop’s charging port.

Outer Diameter (OD)

The outer metal ring of the adapter tip. It must match the outer diameter of your laptop’s charging port. Measured in millimeters.

Inner Diameter (ID)

The inner metal ring of the adapter tip. It should match the measurement of your laptop’s power socket. Measured in millimeters.

Laptop Charger Tip Size Chart

The chart above shows common charger tip sizes measured in millimeters. There are two main tip types:

Barrel tips — found on most older laptops
Cloverleaf tips — more common on newer laptops

How to Measure Your Laptop Charger Pin

If you have your original charger, the easiest approach is to match it visually with a replacement. If you don’t have the original, measure with a digital caliper for accurate results.

Measure the outer diameter from side to side across the middle of the tip
Measure the inner diameter of the hole in the center of the tip
Cross-check both measurements with the size chart above

Important: Once you have found a charger with the correct pin size, also verify that the volts and amps match your laptop’s requirements. Using the correct voltage and amperage is just as important as the pin size to avoid damage.

If your laptop uses a USB-A, USB-B, or USB-C connector, you can technically charge on any compatible USB charger. However, check the wattage — a low-power charger will charge your laptop much more slowly.

FAQ (How to Know the Pin Size of Laptop Charger)

How much voltage is required to charge a laptop?

Most laptops require between 11 and 20 volts to charge. The exact requirement depends on your laptop model and battery. Always match the voltage of the replacement charger to your original charger’s label.

How do you fix a laptop charger tip?

Laptop charger tips use a polarity system marked with (+) or (-) symbols. If your charger is plugged in but not charging, try rotating the adapter 180 degrees. If the tip is physically damaged, replace the charger rather than attempting a repair.

Can I charge my laptop with a different charger?

Yes, if the pin size, voltage, and amperage all match. When traveling, a universal adapter with multiple tips is the safest option. Never use a charger with the wrong voltage as it can permanently damage the battery or motherboard.

Conclusion

Knowing your laptop charger pin size ensures you buy the right replacement without damaging your laptop. Match both the outer and inner diameter, and always verify the voltage and amperage before purchasing a new charger.