Apple recommends the following pairings:

12-inch MacBook with USB-C port with the 30W USB-C Power Adapter13-inch MacBook Pro with Thunderbolt 3 (USB-C) ports with the 61W USB-C Power Adapter15-inch MacBook Pro with Thunderbolt 3 (USB-C) ports with the 87W USB-C Power Adapter

Whats in the Box

Apple USB-C Charge Cable (1 m)