Pick your iPhone and your charger to see if it works and how fast, based on Apple’s guidance.
What wattage charger do I need for my iPhone?
For most iPhones, a 20W USB-C Power Delivery adapter is enough to fast charge. Apple‘s minimum is 18W. The newest models can charge faster with more: Apple recommends 40W or higher for the iPhone 17, 17 Pro and 17 Pro Max, and a 60W-capable adapter (like its 40W Dynamic Power Adapter with 60W Max) for the iPhone 18 Pro models and iPhone Duo. A bigger charger is safe, because your iPhone only takes the power it can use.
How to Use the iPhone Charger Wattage Checker
This free iPhone charger wattage checker tells you whether the charger in your hand is fast enough, based on Apple’s published charging guidance. Pick your iPhone and your charger, and it tells you whether that charger works with your model and how fast it charges.
- Choose your iPhone. Not sure which one you have? Use our iPhone model number lookup.
- Choose your charger: a USB-C adapter, a Samsung or other Android charger, an old USB-A cube, Apple’s MagSafe Charger, a Qi2 magnetic charger or a basic Qi pad.
- Enter the adapter’s wattage. It’s printed in small text on the adapter itself. Look for a number followed by “W”. If you only see volts (V) and amps (A), multiply them: 5V × 2A = 10W. For MagSafe and wireless pads, enter the wattage of the adapter plugged into them.
- Read your result: whether it works with your iPhone, how fast, and what you’d need for top speed.
What Each Verdict Means
- Top speed: your iPhone’s fastest charging, according to Apple’s guidance for your model.
- Fast: it fast charges, but not at your model’s top speed.
- Works / Not fast: it charges at normal speed.
- Slow: it works, but a full charge can take hours.
- Won’t work: this charger can’t charge your iPhone, like a wireless pad with an iPhone 7 or older.
How Much Wattage Does an iPhone Need?
For wired charging, Apple lists the adapter each model needs in its Power adapters for iPhone guide and its Fast charge your iPhone page. Most recent iPhones need a USB-C Power Delivery adapter of around 20W to fast charge, while the newest Pro models reach their fastest speeds with a higher-wattage adapter. The key is USB Power Delivery (USB-PD) — the charging standard defined by the USB Implementers Forum. An older USB-A brick can’t fast charge an iPhone at any wattage.
For wireless charging, the pad matters as much as the adapter behind it. MagSafe and Qi2-certified chargers are faster than basic Qi pads, and Apple’s page on iPhone charge speeds notes that wireless chargers below 10W are slow. Our Qi2 vs MagSafe guide compares the options.
Got a Slow Result? What to Do Next
If your charger scores Slow or Normal, upgrading to a USB-C PD adapter is usually the single biggest speed improvement. To see what that change means in minutes, run your numbers through the iPhone charging time calculator. If your charger scores Optimal but your iPhone still charges slowly, the cause is somewhere else — our guide on why your iPhone is charging slowly ranks the usual suspects, and if it’s not charging at all, see iPhone not charging when plugged in.
Frequently Asked Questions
Can I use my iPad or MacBook charger on my iPhone?
Yes. Any USB-C Power Delivery charger is safe — your iPhone only draws the power it’s designed to accept.
Why does my iPhone say “Slow Charger”?
On iOS 18 and later, iPhone shows this on the Lock Screen and in Settings → Battery when a higher-wattage charger would charge it faster. See our explainer on the Slow Charger message on iPhone.
Does the cable affect charging speed?
Yes. A damaged or low-quality cable can limit power even with a good adapter, so try a known-good USB-C cable if your results don’t match the verdict.