Free tool
How Many mAh to Charge iPhone?
Pick your iPhone model, tell us your power bank size, and see how many full charges you will actually get once conversion losses have taken their cut.
Power bank 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 will show you how many full charges you will get once conversion losses have taken their cut.
The battery figure fills in automatically. Using a different phone? Choose “Another phone” and type its battery capacity.
The big number on the box. Tap a common size:
Pick a phone and a power bank
We will work out your real-world charges
Power banks deliver about 85% of the number printed on the box. We will do that maths for you.
Have a power station rated in Wh instead of mAh? Divide its Wh by 3.7, then multiply by 1,000 to get a comparable mAh figure. For example, a 256Wh station is about 69,000mAh.
Quick maths
The short answer
One full iPhone charge needs about 1.2x the phone’s battery in rated power bank mAh. An iPhone battery holds between roughly 3,100 and 5,100mAh depending on the model. A power bank never delivers its printed number: after charging losses, about 85% of the rated capacity reaches your phone. So one full iPhone 16 charge needs about 5,700 rated mAh, which is why a 5,000mAh bank falls just short. That 1.2x maths is exactly what this 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.
The conversion tax
Why your 10,000mAh bank is not really 10,000mAh
The number on the box is not a lie, but it is not what reaches your phone either. The cells inside a power bank store energy at about 3.7 volts, and your iPhone charges over USB at 5 volts, so the bank steps the voltage up on the way out.
Measure what comes out at that higher voltage and you get a smaller mAh figure. Anker’s own worked example lands at about 6,300mAh from a 10,000mAh bank, and that is where the widely quoted 63% comes from. The figure is real, but it is the wrong one to compare against your phone, because your phone’s battery is rated at its own voltage, close to the bank’s, and not at 5 volts. Comparing the two straight off is like dividing a distance in miles by one in kilometres.
Convert back and the two voltage steps cancel out, leaving only what is genuinely lost: heat and the charging circuit, which costs about 15% on a good bank. So roughly 85% of the printed capacity reaches your phone, and that is what our calculator uses. On an iPhone 16 Pro Max that means a 10,000mAh bank has about 8,500mAh of usable charge for a 4,685mAh battery: one full charge with most of a second 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.
Every model
How many mAh to charge iPhone 13 to 17
Working out how many mAh to charge iPhone models starts with the battery inside, and Apple does not print it on the box. Here is every model from the iPhone 13 onwards, using the capacities compiled by Macworld, with the rated power bank mAh you would need for one full charge.
| Model | Battery (mAh) | One charge needs (rated mAh) |
|---|---|---|
| iPhone 13 mini | 2,438 | ~2,900 |
| iPhone 13 | 3,240 | ~3,800 |
| iPhone 13 Pro | 3,095 | ~3,600 |
| iPhone 13 Pro Max | 4,352 | ~5,100 |
| iPhone 14 | 3,279 | ~3,900 |
| iPhone 14 Plus | 4,325 | ~5,100 |
| iPhone 14 Pro | 3,200 | ~3,800 |
| iPhone 14 Pro Max | 4,323 | ~5,100 |
| iPhone 15 | 3,349 | ~3,900 |
| iPhone 15 Plus | 4,383 | ~5,200 |
| iPhone 15 Pro | 3,274 | ~3,900 |
| iPhone 15 Pro Max | 4,422 | ~5,200 |
| iPhone 16 | 3,561 | ~4,200 |
| iPhone 16 Plus | 4,674 | ~5,500 |
| iPhone 16 Pro | 3,582 | ~4,200 |
| iPhone 16 Pro Max | 4,685 | ~5,500 |
| iPhone 16e | 3,961 | ~4,700 |
| iPhone 17 | 3,692 | ~4,300 |
| iPhone 17 Pro | 4,252 | ~5,000 |
| iPhone 17 Pro Max | 5,088 | ~6,000 |
| iPhone Air | 3,149 | ~3,700 |
| iPhone 17e | 4,005 | ~4,700 |
Battery capacities compiled by Macworld; “one charge needs” = battery mAh divided by 0.85 (the 85% real-world yield). Capacities checked July 2026.
Size guide
What each bank delivers in practice
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 16 Pro Max charges |
|---|---|---|---|
| 5,000mAh | ~4,200mAh | 1.2 | 0.9 |
| 10,000mAh | ~8,500mAh | 2.4 | 1.8 |
| 20,000mAh | ~17,000mAh | 4.8 | 3.6 |
| 26,800mAh | ~22,800mAh | 6.4 | 4.9 |
| 30,000mAh | ~25,500mAh | 7.2 | 5.4 |
| 40,000mAh | ~34,000mAh | 9.5 | 7.3 |
The 5,000mAh row is the one to watch. It will just about fill a standard iPhone once, but on a Pro Max it is a top-up rather than a full refill. Banks above 27,000mAh need airline approval; check with our mAh to Wh calculator.
Practical tips
Get more out of the bank you already own
Use a decent cable. A worn or badly made cable wastes power as heat and can throttle charging speed. Our best USB-C cable for iPhone guide covers what is worth buying.
Wired beats magnetic. MagSafe and Qi are convenient, but wireless charging loses noticeably more energy than a cable. When you are rationing a bank, plug in.
Keep it warm. Lithium cells hate the cold. A bank that lives in an outside pocket in winter delivers fewer charges than the same bank kept inside a bag.
Charge in fewer, bigger sessions. Letting the phone drop to 20% and charging it properly wastes less of the bank than constant little top-ups, because every session carries an overhead.
Phone refusing to charge at all? That is rarely the bank. Work through our iPhone not charging guide first.
Before you fly
Flying with your power bank?
Airlines do not 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
Frequently asked questions
How many mAh to charge iPhone 15?
The iPhone 15 has a 3,349mAh battery. Because a power bank delivers about 85% of its printed capacity, one full charge needs about 3,900 rated mAh. A 10,000mAh bank will do it about 1.9 times.
How many mAh to charge iPhone 16?
The iPhone 16 has a 3,561mAh battery, so one full charge needs about 5,700 rated mAh from a power bank. A 5,000mAh bank charges it fully about once; a 10,000mAh bank charges it fully about 2.4 times.
How many mAh to charge iPhone 14?
The iPhone 14 has a 3,279mAh battery, so one full charge needs about 5,200 rated mAh from a power bank. A 10,000mAh bank will charge it fully about 1.9 times.
How many mAh is the iPhone 15 Pro Max?
The iPhone 15 Pro Max has a 4,422mAh battery, the largest of the iPhone 15 line-up. For one full charge from a power bank, budget about 7,000 rated mAh.
Why does my 10,000mAh power bank not charge my iPhone three times?
Charging losses, mostly heat, take roughly 15% of what the bank holds, so a 10,000mAh bank has about 8,500mAh of usable charge. That is about 1.8 to 2.7 full iPhone charges depending on the model, not three. It is normal, not a faulty bank.
What size power bank should I buy for an iPhone?
For a day out, 10,000mAh covers one to nearly two full charges of any iPhone. For a weekend or heavy use, go 20,000mAh. If you fly a lot, 26,800mAh is the biggest size that clears airline rules without approval.
Does the calculator work for Android phones and iPads?
Yes. Choose “Another phone” and type the device’s battery capacity in mAh, which a quick search for your model will give you. The conversion maths is the same for any phone or tablet. Laptops are measured in watt-hours instead; for those, see our best 20,000 mAh power banks guide.
Can I use a portable power station to charge my iPhone?
Yes, but it is overkill for a phone. A 256Wh power station holds about 69,000mAh equivalent, enough for roughly 12 full iPhone 16 charges. Power stations make sense for camping or laptops, not pocket charging, and they cannot fly (all are over the 160Wh limit). If you want something for a trip, a 20,000 to 26,800mAh power bank is far lighter and flight-legal.
Keep reading
Related guides
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Built for people who check the numbers
SmartGadgetKit is an independent site. We buy what we review and recommend what survives the spreadsheet.
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.
