Myountek — USB-C Cables and Charging Power | myountek.com
Every USB power step in one table, with the volts and amps behind each watt figure.
The lowest step on this ladder is 2.5 W. USB 1.0 and 2.0 ports provided up to 2.5 W, a figure set before USB 3.0 arrived.
USB 3.0 raised port output to 4.5 W, and the Battery Charging specifications pushed it to 7.5 W. These three steps all operate at 5 V and differ only in the current the port supplies.
The USB-C connector adds two default modes above the Battery Charging figure. Without a Power Delivery contract, a USB-C port may provide 5 V at either 1.5 A or 3 A — that is 7.5 W or 15 W depending on the mode the port selects.
On narrow screens, swipe or scroll the plate sideways.
The standard USB Power Delivery range covers most 5 V to 20 V consumer devices up to a maximum of 100 W. This is the ceiling for chargers that do not implement Power Delivery 3.1.
Power Delivery 3.1, released in 2021, raised the maximum power to 240 W. The Extended Power Range achieves this at 48 V and 5 A, which is why both the charger and the cable must be rated for the higher voltage.
Read the table top to bottom to find where your device sits. The volts and amps columns show what the charger label must state before the wattage figure can be verified.
Further reading