How many watts does a MacBook need? Check your charger on the Mac
How much wattage a MacBook needs to charge, what happens with a lower watt charger, and how to see the wattage your Mac is actually getting.
How many watts does a MacBook charger need?
At least the wattage of the adapter that came with the Mac: 30 W or more for a MacBook Air, more for the larger MacBook Pro models. A higher watt USB-C charger is safe; the Mac only draws what it needs.
Can I use a lower watt charger on a MacBook?
Yes, it charges more slowly, and under heavy use it may not keep up, so the battery still drains: why a MacBook drains while charging.
How do I see the wattage my Mac is getting?
pmset -g adapterSystem Information, Power also lists the AC charger wattage.
Common questions
Can I charge a MacBook Air with a 20W charger?
It charges, slowly, and may not keep up while you work. The 30 W adapter or higher charges at the normal rate.
Is a higher watt charger safe for a MacBook?
Yes. USB-C power delivery negotiates the amount, and the Mac only draws what it needs.