How Many mAh to Charge iPhone 15, 16 or 17? Charges Calculator
How many charges will your power bank give?
How many mAh to charge iPhone 15, 16 or one of the newer models? It depends on the phone’s battery and on your power bank’s real, usable capacity. Pick your iPhone, tell us the power bank size, and we’ll show you how many full charges you’ll get once conversion losses have taken their cut.
The battery figure fills in automatically. Using a different phone? Type its battery capacity instead.
The big number on the box. Tap a common size:
Pick a phone and a power bank
We’ll work out your real-world charges
Power banks deliver about two thirds of the number printed on the box. We’ll do that maths for you.
The short answer
An iPhone battery holds between roughly 3,100 and 5,100mAh depending on the model. A power bank never delivers its printed number, though. After voltage conversion and circuit losses, about 63% of the rated capacity reaches your phone. So the working rule is simple: for one full charge, you need about 1.6 times your iPhone’s battery figure in rated power bank mAh. One full iPhone 16 charge needs about 5,700 rated mAh, which is why a 5,000mAh bank falls just short. That 1.6x maths is exactly what this power bank charges calculator does for you. The same rule scales: a 20,000mAh bank runs to nearly three Pro Max charges, while a 5,000mAh pocket bank is a top-up rather than a refill.
Why your 10,000mAh bank is really a 6,300mAh bank
The number on the box isn’t a lie. Manufacturers measure it somewhere you can’t use it. The lithium cells inside a power bank store energy at 3.7 volts, but your iPhone charges over USB at 5 volts or more. Stepping the voltage up costs capacity straight away: multiply by 3.7, divide by 5, and your 10,000mAh is down to 7,400 before anything else happens.
Then the charging circuit takes its share as heat. A good bank runs at 80 to 90% efficiency. Anker’s own worked example lands at about 6,300mAh usable from a 10,000mAh bank. Call it 63% of the printed figure, which is exactly what our calculator uses. On an iPhone 16 Pro Max that means a 10,000mAh bank delivers about 6,300mAh into a 4,685mAh battery: one full charge with about a third of the next in reserve.
Treat the result as a solid estimate rather than a promise. A tired cable or a cold day will nudge the real number down a little.
How many mAh to charge iPhone 13 to 17: every model
Working out how many mAh to charge iPhone models starts with the battery inside, and Apple doesn’t print it on the box. Here’s every model from the iPhone 13 onwards, using the capacities compiled by Macworld, with the rated power bank mAh you’d need for one full charge.
| Model | Battery (mAh) | One full charge needs (rated mAh) |
|---|---|---|
| iPhone 13 mini | 2,438 | ~3,900 |
| iPhone 13 | 3,240 | ~5,200 |
| iPhone 13 Pro | 3,095 | ~4,900 |
| iPhone 13 Pro Max | 4,352 | ~6,900 |
| iPhone 14 | 3,279 | ~5,200 |
| iPhone 14 Plus | 4,325 | ~6,900 |
| iPhone 14 Pro | 3,200 | ~5,100 |
| iPhone 14 Pro Max | 4,323 | ~6,900 |
| iPhone 15 | 3,349 | ~5,300 |
| iPhone 15 Plus | 4,383 | ~7,000 |
| iPhone 15 Pro | 3,274 | ~5,200 |
| iPhone 15 Pro Max | 4,422 | ~7,000 |
| iPhone 16 | 3,561 | ~5,700 |
| iPhone 16 Plus | 4,674 | ~7,400 |
| iPhone 16 Pro | 3,582 | ~5,700 |
| iPhone 16 Pro Max | 4,685 | ~7,400 |
| iPhone 16e | 3,961 | ~6,300 |
| iPhone 17 | 3,692 | ~5,900 |
| iPhone 17 Pro | 4,252 | ~6,800 |
| iPhone 17 Pro Max | 5,088 | ~8,100 |
| iPhone Air | 3,149 | ~5,000 |
| iPhone 17e | 4,005 | ~6,400 |
What each size delivers in the real world
Real-world full charges after conversion losses, using the two most-asked-about models as the yardstick.
| Power bank | Usable capacity | iPhone 16 charges | iPhone 15 Pro Max charges |
|---|---|---|---|
| 5,000mAh | ~3,100mAh | 0.9 | 0.7 |
| 10,000mAh | ~6,300mAh | 1.8 | 1.4 |
| 20,000mAh | ~12,600mAh | 3.5 | 2.8 |
| 26,800mAh | ~16,900mAh | 4.7 | 3.8 |
That 5,000mAh row surprises people. The smallest banks are brilliant pocket insurance, but they won’t take a modern iPhone from flat to full.
Get more out of the bank you already own
Calculator told you what size you need? These are the banks worth your money at each size.
Flying with your power bank?
Airlines don’t care about mAh. They measure in watt-hours, and anything over 100Wh needs approval. Our mAh to Wh calculator does that conversion and gives you the verdict, and the full airline rules guide covers limits, counts and the checked-bag ban.
Quick answers
How many mAh to charge iPhone 15?
How many mAh to charge iPhone 16?
How many mAh to charge iPhone 14?
How many mAh is the iPhone 15 Pro Max?
Why doesn’t my 10,000mAh power bank charge my iPhone three times?
What size power bank should I buy for an iPhone?
Does the calculator work for Android phones and iPads?
Battery capacities compiled by Macworld; conversion method per Anker’s published efficiency figures. Capacities checked July 2026. Results are estimates: cable quality, temperature and charging speed all move the real number slightly. See how we test and score the banks we recommend.
