Power bank calculator
Pick a power bank and a phone. See how many full charges you get and how many extra hours of use that adds, including for an older phone.
This calculator needs JavaScript. The table further down shows the results for a common 10,000mAh bank without it.
This is an estimate, not a promise. Real results change with screen brightness, signal, temperature, the cable and how warm the phone gets while charging. Wireless and magnetic charging waste more energy than a cable, so expect fewer charges with them.
Results for a common 10,000mAh bank
A typical 10,000mAh pack holds 37Wh (Anker Zolo 10K, INIU P50-E1). Here is what that gives each listed phone when the phone is new, using a cable and normal use.
| Phone | Battery | Full charges | Extra hours |
|---|---|---|---|
| Apple iPhone 18 Pro Max | 5,391mAh | 1.1–1.2 | 21–24 |
| Apple iPhone 18 Pro | 4,056mAh | 1.4–1.7 | 24–28 |
| Apple iPhone 17 Pro Max | 4,823mAh | 1.2–1.4 | 21–25 |
| Apple iPhone 17 Pro | 3,998mAh | 1.4–1.7 | 22–26 |
| Apple iPhone 17 | 3,692mAh | 1.6–1.8 | 23–27 |
| Apple iPhone Air | 3,149mAh | 1.8–2.1 | 23–27 |
| Apple iPhone 16 | 3,561mAh | 1.6–1.9 | 25–30 |
| Google Pixel 11 | 4,985mAh | 1.2–1.3 | 18–21 |
| Google Pixel 11 Pro | 4,850mAh | 1.2–1.4 | 19–22 |
| Google Pixel 10 | 4,970mAh | 1.2–1.3 | 14–16 |
| Google Pixel 10a | 5,100mAh | 1.1–1.3 | 17–20 |
| Samsung Galaxy S26 Ultra | 5,000mAh | 1.1–1.3 | 19–22 |
| Samsung Galaxy S26 | 4,300mAh | 1.3–1.6 | 20–24 |
| Samsung Galaxy A57 | 5,000mAh | 1.1–1.3 | 16–19 |
How the calculator works
1. Energy in the bank. We use the watt-hours (Wh) the maker prints. For your own bank, we work it out: mAh × volts ÷ 1,000.
2. Energy that reaches the phone. Some energy is lost as heat in the bank, the cable and the phone. Anker says power banks normally deliver about 60% to 70% of their capacity, so we show a low and a high figure.
3. Size of the phone battery. Phone mAh × 3.87V ÷ 1,000. Anker gives 3.87V as the typical phone battery voltage.
4. Hours of use. We use GSMArena's lab battery test for each phone, run from full to empty at the same screen brightness. Light uses its video test, normal uses its overall "Active Use" score and heavy uses its gaming test. These are screen-on hours, not standby.
5. Phone age. Batteries hold less as they age. Apple and Google say their recent phones keep about 80% of capacity after 1,000 full charges. Samsung's EU labels list 1,200 for the Galaxy models here. We assume about one full charge a day and draw a straight line from 100% when new down to 80% at that rating. Past the rating (4+ years) we carry the line on, which is only a rough guess.
An older phone doesn't use more power. It just holds less. So the bank gives an old phone more, smaller charges, and the total extra hours stay about the same. What drops is how long the phone lasts on its own.
Questions
How many times will a 10,000mAh power bank charge my phone?
For current phones, about 1.1 to 2.1 full charges by cable. A 10,000mAh pack holds about 37Wh, and roughly 60% to 70% of that reaches the phone. Smaller phone batteries get more charges.
Why don't I get the full mAh out of my power bank?
The mAh on the box is measured at the cell's own voltage (about 3.7V). Converting it to charge a phone, plus the cable and the phone's charging circuit, turns some energy into heat. Anker says power banks normally deliver about 60% to 70% of their capacity.
Does an older phone get more charges?
Yes, but each charge is smaller. An older battery holds less, so it fills up sooner. The total extra hours of use stay about the same, because the phone uses the same power. What drops is how long the phone lasts on its own.
Is wireless or MagSafe charging included?
No. The figures assume a cable. Wireless and magnetic charging waste more energy as heat, so expect fewer charges.
How accurate is this?
It is an estimate. It uses maker figures and lab battery tests at a fixed screen brightness. Your brightness, signal, apps and temperature will move the real result up or down.
Choosing a bank? Read our power bank buying guide.
Sources
All figures were checked on October 29, 2026. Product pages may change.
- Delivered energy (60% to 70%): Anker support: why a power bank gives less than advertised
- Typical phone voltage (3.87V) and cell voltage (3.7V): Anker support: power bank label details and Anker support: rated capacity
- Hours of use: GSMArena Battery Life Test 2.0 results and how GSMArena tests
- Phone battery sizes and EU charge-cycle ratings: GSMArena spec pages for each phone, for example iPhone 17, Pixel 11 and Galaxy S26. Apple doesn't publish mAh, so iPhone figures come from GSMArena. For Pro iPhones we use the SIM-tray version; eSIM-only versions have slightly bigger batteries.
- Battery ageing: Apple: iPhone battery and performance, Google: Pixel battery health, EU energy label rules (2023/1669) and, for phones not on our list, the EU minimum of 800 cycles in EU ecodesign rules (2023/1670)
- Power banks (maker pages): Nitecore NB Air, Nitecore NB10000 Gen4, Anker Zolo 10K 30W, Anker Prime 26K 300W, UGREEN Nexode 145W, INIU P50-E1, Goal Zero Venture 35, Anker Nano 5K MagGo Slim (its 19.35Wh comes from the label shown in a third-party teardown, not the maker page)