For 20W charger, the max. power output is 20W total.
For 30W charger, the max. power output is 30W total.
For 65W charger, the max. power output is 65W total.
For 100W charger, the max. power output is 100W total.
For 30W, 65W and 100W chargers, when charging more than one device simultaneously, total max. power output is 30W, 65W and 100W, respectively. You can also check detailed power output information from specification on product page.