Quick answer: size the charger for your biggest device, or for everything added up if you charge at once. A 65W charger covers a phone, a tablet and a thin laptop, and big laptops need 96–140W. Any USB-C cable carries 60W, above that you need a 100W (5A) cable, and above 100W a 240W EPR cable. Pick your devices below.
What charger do I need?
How the calculator decides
USB Power Delivery is a negotiation: the charger advertises what it can supply and the device asks for only what it can take. That is why a 140W charger is perfectly safe for earbuds, and why the right charger is simply the one that covers your biggest need. Our guide to USB-C charger wattage covers each device class in detail.
| Cable type | Max power | How to spot it |
|---|---|---|
| Basic USB-C (no e-marker) | 60W (3A at 20V) | Most cables in your drawer |
| E-marked, 5A | 100W (5A at 20V) | Printed "100W" or "5A" on the cable or box |
| EPR (USB PD 3.1) | 240W (5A at 48V) | Marked "240W"; needed for anything above 100W |
A cable that is too weak never causes damage. Everything simply negotiates down to the cable's limit, so if a laptop charges slowly on a big charger, suspect the cable first.
Frequently Asked Questions
What wattage USB-C charger do I need for my phone?
Twenty watts is the minimum for fast charging an iPhone, and 30 to 40W gives full speed on current models. Samsung Galaxy phones need a 45W charger with PPS for Super Fast Charging. Most other Android phones top out around 25 to 30W on standard USB-C chargers.
Can I use a higher-wattage charger than my device needs?
Yes. USB-C chargers only supply the power a device requests, so a 100W or 140W charger is safe for a phone or earbuds. A bigger charger is headroom, not risk.
Does the USB-C cable affect charging speed?
Yes. Basic USB-C cables are limited to 60W, 5A e-marked cables to 100W, and only 240W EPR cables can carry more than 100W. A 60W cable on a 140W laptop charger will cap charging at 60W.
What charger do I need for a laptop and phone at the same time?
Add up the wattages. A 35W MacBook Air plus a 30W iPhone needs about 65W, so a two-port 65W GaN charger covers both. Check that one port can still deliver the laptop wattage while both are plugged in.
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