Compare · The PD 3.1 boundary
100W vs 140W: a different standard, not a bigger number.
100W is the ceiling of USB PD 3.0 at 20V/5A. 140W is PD 3.1, which introduces a 28V rail — a new voltage, a new cable requirement, and the only way to fast-charge a 16″ MacBook Pro over USB-C.
Spec sheet, side by side
| 100W | 140W | |
|---|---|---|
| Standard | USB PD 3.0 | USB PD 3.1 (Extended Power Range) |
| Top rail | 20V/5A | 28V/5A |
| Cable required | 5A e-marked, 100W rated | EPR cable rated to 240W |
| Ports | 3–4 typical | 2–3 typical, sometimes 4 |
| Size class | Large wall brick or small desktop | Larger again; many are desktop units with a cord |
| Best-suited devices | MacBook Pro 14″, ultrabooks, multi-device desks | MacBook Pro 16″, workstation laptops, everything below |
The 28V rail is the entire point. A device that supports PD 3.1 asks for 28V and takes 140W; a device that does not simply negotiates 20V and behaves exactly as it would on a 100W adapter. Nothing is lost by owning the bigger unit — see can I use a higher-wattage charger.
Where each one wins
100W wins on price per watt, cable compatibility and bulk. Every 5A e-marked cable already in your bag works at 100W. Four-port 100W units are the desk default, and the tier is mature enough that competition has pushed cost per watt below the 140W class.
140W wins for exactly one laptop family, decisively. The 16″ MacBook Pro is specified at 140W and only reaches its fast-charge behaviour on a PD 3.1 adapter with an EPR cable. Feed it 100W and it charges — slowly, and it will draw from the battery during sustained renders. Workstation-class Windows laptops that accept USB-C charging behave the same way. Class pages: 100W adapters, 140W adapters.
Verdict: 100W unless you own a 16″ MacBook Pro
The line here is drawn by hardware, not preference. If your heaviest device is a MacBook Pro 14″, an ultrabook, or a desk full of phones and tablets, 100W delivers every watt anything will request and is the better watts-per-dollar buy. If your heaviest device is a 16″ MacBook Pro or a workstation laptop that lists 140W input, buy 140W and budget for an EPR cable in the same order — 100W is a compromise you will feel under load. The middle path is a 140W multi-port unit that runs as a 100W-class desk charger most of the time and has the 28V rail waiting: that is the pick for anyone who expects a bigger laptop next. Related: 65W vs 100W, 140W vs 240W, Apple 96W vs 140W.
- 100W
UGREEN Nexode 100W 4-Port
The 100W side. Laptop plus three accessories, standard 5A cables, mature price per watt.
- Output
- 100W total
- Ports
- 3× C, 1× A
- Standard
- PD 3.0
- 140W
Apple 140W USB-C Power Adapter
The 140W reference: PD 3.1 at 28V, the profile the 16″ MacBook Pro is designed around.
- Output
- 140W PD 3.1
- Ports
- 1× USB-C
- Rail
- 28V/5A
- PD 3.1
Anker Prime 140W
The compromise: PD 3.1 headroom in a multi-port body that also works as a 100W-class desk unit.
- Output
- 140W total
- Ports
- 3
- Standard
- PD 3.1
Every head-to-head is listed at charger comparisons.
FAQ
Can a 100W charger run a 16-inch MacBook Pro?
Yes, it will charge and run the machine for ordinary work. It cannot fast-charge it, and under sustained heavy load the laptop will supplement from the battery.
What makes 140W require a different cable?
PD 3.1 raises the voltage to 28V. Only cables carrying an EPR e-marker rated to 240W are certified for it, and the adapter refuses to offer 28V to a cable that does not declare that rating.
Is 140W wasted on a phone or an iPad?
No watts are wasted — the device negotiates its own contract, so a phone still takes about 20 to 27W. What you pay for is size and price, not risk.