Guide · 6 min read
240W over USB-C, explained.
USB PD 3.1 lifted the ceiling from 100W to 240W without raising the current limit by a single amp. Everything about Extended Power Range follows from that one design choice — including why the cable is not optional and why so few devices actually ask for it.
The EPR rails
Standard Power Range PD stops at 100W because it stops at 20V, and 5A is the hard current limit for a USB-C connector. PD 3.1 keeps 5A and adds three higher fixed voltages instead:
| Rail | Power | What uses it |
|---|---|---|
| 20V / 5A (SPR) | 100W | Most USB-C laptops and docks |
| 28V / 5A | 140W | Apple 140W, 16-inch MacBook Pro |
| 36V / 5A | 180W | Rare — a few workstation and gaming designs |
| 48V / 5A | 240W | Desk chargers, some monitors, industrial gear |
EPR also adds AVS, Adjustable Voltage Supply: instead of jumping between fixed rails, an EPR source can be asked to hold any voltage from 15V up to its maximum in 100mV steps. It is the same idea as PPS, scaled up for laptops, and it lets a machine sit exactly at the voltage its power stage prefers.
The cable is part of the standard
An EPR contract will not be offered at all unless the cable declares itself capable. The e-marker in a 240W cable advertises 50V and 5A, and a source that reads anything less simply withholds every rail above 100W — no warning, no error, just a quieter contract. A 100W 5A cable is not an EPR cable, and neither is a Thunderbolt 4 cable by default. Look for "Certified USB 240W" on the packaging or "240W" printed on the connector shell.
What actually exists at 240W
On the source side, 240W is real and shipping: multi-port GaN desk chargers with a single 240W-capable port or a 200W+ shared budget, a handful of high-output power stations, and certified cables from most cable brands. On the sink side, the picture is thinner. No mainstream laptop requests the full 240W over USB-C today; the highest common single-device draw is 140W, and most performance laptops that need more still use a barrel jack or a proprietary connector to reach their full system power. Displays and docks are the other realistic consumers, since a monitor delivering 100W to a host while running its own panel needs a large input budget.
That makes the honest case for a 240W-class charger a total budget case rather than a single-device one: a 16-inch MacBook Pro at 140W plus a tablet at 35W plus two phones at 25W each is 225W of simultaneous draw, and only a genuinely large brick services that from one outlet without throttling. If you have one laptop, a 100W or 140W unit is the right size and costs far less.
- 240W
240W 4-Port GaN Desk Charger
One outlet for a full desk: laptop, tablet and two phones without the ports fighting over a small budget.
- Output
- 240W total
- Ports
- 3× C, 1× A
- Standard
- PD 3.1 EPR
- Best for
- Multi-device desks
- 240W
Certified 240W USB-C Cable
The mandatory half of EPR. Declares 50V/5A over its e-marker, without which no source offers more than 100W.
- Rating
- 240W / 48V 5A
- Data
- USB 2.0 on most
- Length
- 1–2m
- Best for
- 140W and 240W kit
- 140W
Apple 140W USB-C Power Adapter
The most common PD 3.1 device in the wild: a 28V rail for the 16-inch MacBook Pro's fast charge.
- Output
- 140W PD 3.1
- Rail
- 28V
- Ports
- 1× USB-C
- Best for
- MacBook Pro 16-inch
Further reading: 140W vs 240W for the sizing decision, MacBook charging for the 28V case, and 240W GaN chargers for current hardware.
FAQ
Do I need a 240W charger?
Almost certainly not for one device. It makes sense as a shared budget for a desk running a 140W laptop plus tablets and phones at the same time.
Will a 240W charger damage a phone?
No. The phone negotiates its own 20–27W contract and the extra rails are never offered to it. The device always writes the contract.
Can I use my existing 100W cable for 240W?
No. A 100W cable's e-marker declares 20V/5A, and an EPR source will not go above 100W without a cable declaring 50V/5A.
Which laptops actually draw 240W over USB-C?
As of 2026, essentially none in the mainstream. 140W is the practical top of the USB-C sink range; higher-draw machines still use barrel jacks or proprietary connectors.