Apple 40W Dynamic Power Adapter (60W Max) on a MacBook Air: Measured
Apple's 40W Dynamic Power Adapter measured on a MacBook Air M5: it advertises both of its ratings, and the Mac takes the 60 W peak profile marked DPS.
The Apple 40W Dynamic Power Adapter with 60W Max - a charger that puts two different wattages on its own label. Tested against a MacBook Air M5 with a low battery, per the methodology.
The numbers
| Rated | 40 W sustained / 60 W max |
| Negotiated | 60 W (20 V up to 3 A) - DPS |
| Live draw | 56.1 W (19.3 V at 2.91 A) |
| Protocol | USB PD 3.0 |
Profile menu:
| Profile | Rail |
|---|---|
| 15 W | 5 V up to 3 A |
| 27 W | 9 V up to 3 A |
| 40 W | 20 V up to 2 A |
| 45 W | 15 V up to 3 A |
| 60 W | 20 V up to 3 A - (DPS) |
What DPS actually means
DPS is Dynamic Power Supply. It’s how one charger honestly advertises two different ratings.
This adapter can sustain 40 W indefinitely, and can supply 60 W for shorter bursts when a device asks for it and thermal conditions allow. Rather than picking one number for the label, it publishes both as real profiles: 40 W at 20 V / 2 A, and 60 W at 20 V / 3 A with the peak flagged.
The Mac took the 60 W rung and settled at 56.1 W live. Under sustained heavy load the adapter can fall back toward its 40 W rating - that’s the design working, not the charger underperforming.
It’s a genuinely clever piece of engineering for a travel charger: near-60 W performance when the laptop is hungry, in a body sized for 40 W duty.
Reading it in the app
USB Connection Information labels the peak profile (DPS) specifically so this is legible. Without that flag, a profile list showing both 40 W and 60 W at the same 20 V rail looks like a contradiction. With it, the two-tier design is obvious at a glance.
Buying one
The Apple 40W Dynamic Power Adapter (60W Max) is the current compact Apple adapter and a sensible default for a MacBook Air - small enough to travel with, and capable of real charging speed rather than a trickle.
The Amazon link above is an affiliate link. As an Amazon Associate I earn from qualifying purchases.