Apple 67W USB-C Power Adapter on a MacBook Air: Measured

Apple's 67W USB-C adapter measured on a MacBook Air: a 65.4 W contract at 3.27 A, requiring a 5A cable to deliver its full power.

Apple 67W USB-C Power Adapter, model A2518, with folding prongs.

Apple’s 67W USB-C power adapter, tested against a MacBook Air with a low battery, per the methodology.

67.0W 45.0W 27.0W 15.6W. Input 100-240V~ 1.65A 50-60Hz. EMC 3956. USB PD Output 20.3V at 3.3A, or 15.0V at 3.0A, or 9.0V at 3.0A, or 5.2V at 3.0A. Liteon Tech Corp. E132068.

The numbers

Rated67 W
Negotiated65.4 W (20 V up to 3.27 A)
Live draw62.5 W (19.7 V at 3.17 A)
ProtocolUSB PD 3.0

Profile menu: 15 W (5 V up to 3 A), 27 W (9 V up to 3 A), 45 W (15 V up to 3 A), 65.4 W (20 V up to 3.27 A).

67W USB-C Power Adapter. Designed by Apple in California, Assembled in China. Model A2518. TM and copyright 2021 Apple Inc.

A 5A cable requirement

The top 65.4 W profile negotiates at 3.27 A. Standard non-e-marked USB-C cables are hard-capped at exactly 3 A (which equals 60 W at 20 V).

Because this adapter’s top profile pushes just slightly past that limit at 3.27 A, it strictly requires a 5A (100W+) e-marked cable to negotiate its full advertised power. If you plug it in using a standard 3A cable, the charger will only advertise up to 60 W, and that’s all you’ll get.