USB-C Power Delivery is the protocol that turned USB from a way to slowly charge a phone into the standard for charging laptops, tablets, monitors, and almost every modern electronic device. Knowing what wattage you need and what your charger actually delivers saves you from slow charging and unnecessarily expensive gear.
This guide covers the protocol, the wattage levels, and how to pick the right charger.
What USB-PD is
USB Power Delivery (USB-PD) is a charging negotiation protocol. When a USB-C charger and a USB-C device connect, they exchange information about what voltages and currents they support. The device asks for the highest wattage that both ends support, and the charger delivers that wattage.
The negotiation happens in milliseconds:
- Device plugs in
- Device tells the charger what voltage levels it supports (e.g., 5 V, 9 V, 15 V, 20 V)
- Charger tells the device what voltage levels and currents it can provide
- They settle on the highest mutually supported wattage
- The charger outputs that voltage and current
- Charging proceeds
The protocol also handles changes in real time. If the device's needs change (e.g., a laptop transitioning from idle to high-performance), the device can request a different voltage and the charger responds.
Why higher voltage matters
Older USB-A charging was fixed at 5 V. To deliver more power, you'd need more current, but cables have current limits before they heat up dangerously. 5 V × 2.4 A = 12 W is roughly the practical limit.
USB-PD's clever insight: instead of cranking up current, crank up voltage. Power = Voltage × Current, so higher voltage at the same current means more power.
USB-PD voltage levels:
- 5 V (PD 1.0 and later): basic phone charging
- 9 V (PD 2.0): fast phone charging (Quick Charge 3.0 era)
- 15 V (PD 2.0): tablet and ultra-thin laptop charging
- 20 V (PD 3.0): laptop charging up to 100 W
- 28 V (PD 3.1): high-wattage laptop charging
- 36 V (PD 3.1): very high-wattage charging
- 48 V (PD 3.1): up to 240 W charging
A cable rated 5 A can deliver:
- 25 W at 5 V
- 75 W at 15 V
- 100 W at 20 V
- 140 W at 28 V
- 180 W at 36 V
- 240 W at 48 V
The cable's amperage rating is the bottleneck, but the higher voltages let you push more power through it.
The wattage tiers
For practical charger selection, USB-C PD chargers come in roughly these tiers:
18-20 W: Phone-only
Charges modern iPhones, Android phones, and small tablets at fast-charge speeds. Doesn't usefully charge laptops; even ultra-thin ones want 30 W+.
Best for: light travelers, weekend trips with phone-only.
30 W: Phone + thin laptops
Fast-charges phones. Charges MacBook Air, Dell XPS 13, and most thin-and-light laptops at full speed. Not quite enough for heavier laptops.
Best for: travelers with thin-and-light laptops.
45 W: Mid-range laptops
Handles most business laptops including Dell Latitude, HP EliteBook, and Lenovo ThinkPad mid-range. Marginal for high-end ultrabooks.
Best for: business travelers with standard laptops.
65 W: Most laptops, the sweet spot
Handles MacBook Pro 14-inch (slow mode), most Windows business laptops, and most consumer laptops. Modern standard for travel chargers.
Best for: most travelers with most laptops.
96 W: MacBook Pro 14-inch fast, larger laptops
The wattage Apple specifies for fast-charging the 14-inch MacBook Pro M-series. Also handles 15-inch consumer laptops at full speed.
Best for: travelers who want fast laptop charging.
100 W: PD 3.0 maximum
The maximum USB-C PD 3.0 wattage. Charges essentially any laptop that supports USB-C charging at full speed except the very largest gaming and workstation machines.
Best for: future-proof investment for one charger.
140 W: MacBook Pro 16-inch
The wattage Apple specifies for fast-charging the 16-inch MacBook Pro M-series. Requires USB-PD 3.1 support on both charger and device.
Best for: 16-inch MacBook Pro owners and high-end Windows laptop users.
240 W: PD 3.1 maximum
The highest wattage USB-C PD currently supports. Used for gaming laptops, workstation laptops, and external display setups. Few devices currently use this.
Best for: gamers and power users with the latest hardware.
Match the charger to the laptop
Most laptops list their required wattage on the original charger or in the spec sheet:
- MacBook Air (M-series): 30 W
- MacBook Pro 13-inch / 14-inch (M-series): 67-96 W
- MacBook Pro 16-inch (M-series): 140 W
- Dell XPS 13: 45 W
- Dell XPS 15: 130 W
- Lenovo ThinkPad X1 Carbon: 65 W
- Lenovo Legion gaming laptops: 100-300 W (depends on model)
- Microsoft Surface Pro: 65 W
- Microsoft Surface Laptop Studio: 102 W
A charger that meets or exceeds your laptop's required wattage charges at full speed. A charger that's below the laptop's required wattage charges slowly (or sometimes not at all if the laptop refuses to charge from underpowered sources).
Cable wattage matters too
A USB-C cable's wattage rating determines how much power can flow through it. Common ratings:
- 60 W rated: covers most phone charging, marginal for laptops above 60 W
- 100 W rated: covers all laptop charging up to 100 W
- 240 W rated: covers PD 3.1 high-wattage applications
A 100 W charger with a 60 W cable delivers only 60 W to the device. The cable is the bottleneck. Look at the cable spec when buying; the markings are usually printed on the cable jacket or on a small tag.
The cables that came with your laptop are usually rated for the laptop's needs. Third-party USB-C cables vary widely; cheaper cables are typically rated 60 W or 100 W.
What changes from older USB charging
For travelers, the practical difference is:
- USB-A charging (cigarette-shaped older USB connector): up to 12 W, phones only
- USB-C basic charging (USB-C without PD support): up to 15 W typically, phones and small tablets
- USB-C PD charging: up to 240 W, phones through high-end laptops
A travel charger with USB-C PD is the right pick because it replaces both your phone charger and your laptop charger. One charger, one cable, one wall outlet.
What to look for in a travel USB-C PD charger
For most travelers:
- 65-100 W total wattage
- 2-3 USB-C ports with PD support
- 1 USB-A port for legacy devices (older phones, cables you already have)
- GaN-based design for size and weight savings
- Foldable plug pins
- Real safety certifications
Specific picks: Anker 735 Nano II (65 W, 3 ports), UGREEN Nexode 100 W (4 ports), Anker Prime 100 W (3 ports).
The bottom line
USB-C Power Delivery is the modern standard for charging anything from phones through high-end laptops. The wattage tiers (30 W, 65 W, 100 W, 140 W) correspond to different device categories.
Pick a charger that meets or exceeds your laptop's spec. Verify your cable's wattage rating. Pair with a multi-port GaN design for travel-friendly form factor.
One USB-C PD charger replaces the separate phone, tablet, and laptop chargers you'd otherwise carry.