What wattage USB-C charger do I need?

Start with the manufacturer’s published supply or fast-charge reference, then make sure the charger port and cable can both support that power class.

The four numbers to compare

1. Device target: the manufacturer’s published supply, recommended-adapter or fast-charge reference used for comparison.
2. Charger total: the overall power budget of the charger.
3. Per-port maximum: a 100W charger may have a 65W USB-C port and a smaller secondary port.
4. Cable power rating: the cable can be the lowest ceiling in the chain.

A practical sizing rule

If your laptop targets 65W, buy a charger with a USB-C port rated for at least 65W and a cable rated for at least 65W. Choosing 100W can provide useful headroom for another device, but only if the charger supports a power split that leaves enough on the laptop port.

Can you use a larger charger?

Normally yes with standards-compliant USB Power Delivery equipment. USB PD is a negotiated system: a charger advertises available profiles and the device requests what it can accept. The charger rating is a maximum capability, not power forced into the device.

What about USB PD 3.1?

USB-IF says USB Power Delivery can support up to 240W with newer Extended Power Range operation. That does not mean every charger, cable or device supports 240W — all parts of the chain still need compatible ratings.

Check a charging setup →

Reviewed September 13, 2026. This guide explains power compatibility, not electrical repair or modification.