In this guide
Most laptops need a USB-C charger rated at 45–100W with Power Delivery (PD) — check your original adapter’s label and match or exceed that number.
- Charger meets or exceeds your laptop’s wattage (45–65W for ultrabooks, 65–100W for 15″+ or performance laptops)
- Charger supports USB Power Delivery (PD)
- Cable is rated for the wattage (60W standard, 100W+ for higher loads)
- Higher-wattage charger used — laptop only draws what it needs
- Charger is under 45W — expect slow or no charging under load
- Charger lacks PD support — limited to 15W max (5V/3A)
- Cable is under-rated for the wattage (e.g., 60W cable used at 100W)
- Gaming or heavy workloads — battery may drain even while plugged in
How to Find Your Laptop’s Required Wattage
Flip your original charger over and read the output label. It will show something like “20V⎓3.25A” — multiply volts by amps to get watts (20 × 3.25 = 65W). That number is your minimum target for a replacement or travel charger.
Wattage by Laptop Type
| Setup | Works? | Need | Note |
|---|---|---|---|
| Thin ultrabook / 13″ laptop | Yes | 45–65W PD charger | 65W covers most models safely |
| 15″–16″ mainstream laptop | Yes | 65W PD charger | Match original adapter rating |
| Performance / gaming laptop | Yes | 100W PD charger | May still drain under heavy load |
| Phone charger (18W or less) | No | 45W+ PD charger | Too slow or no charge at all |
Why Power Delivery (PD) Matters
Standard USB-C without PD tops out at 15W — not enough to charge any laptop. PD allows the charger and laptop to negotiate higher voltages (up to 20V) and currents, which is how you reach the 45–100W range. Always confirm your charger is labelled “USB Power Delivery” or “USB PD.” The USB-IF PD specification defines the exact voltage steps (5V, 9V, 15V, 20V) used in this negotiation.
Don’t Forget the Cable
The charger wattage means nothing if the cable can’t carry it. Standard USB-C cables handle up to 60W. If your laptop needs 100W, you need a cable explicitly rated for 100W or higher. Using an undersized cable will either limit charging speed or cause the connection to drop back to a lower power mode. If you are also using USB-C for video output, see our guide on whether USB-C can connect to HDMI to make sure your cable covers both needs.
Is a Higher-Wattage Charger Safe?
Yes. Laptops only draw the power they need, so a 100W charger on a 65W laptop is perfectly safe. Going higher is fine — going lower causes problems. For more on what USB-C ports can and can’t do, check whether USB-C supports video output on your device.
Bottom line: Match or exceed your laptop’s original wattage, confirm the charger supports USB Power Delivery, and use a cable rated for the load. A 65W PD charger covers most laptops; step up to 100W for larger or performance machines.