Battery & energy · Official calculator
How many times can a power bank charge your phone?
Estimate phone charges from a 10,000mAh or 20,000mAh power bank. The calculation uses Wh, voltage conversion, wired or wireless losses, remaining level, and battery health instead of simply dividing the advertised capacities.
Preparing the calculator.
How it works
Why is the result lower than simple division?
mAh measures charge while Wh is closer to energy. A power-bank cell and a phone battery may use different stated voltages, so dividing 10,000mAh by 5,000mAh misses that difference.
Cell energy is converted to USB output, then passes through a cable or wireless link and the phone charging circuit. Some becomes heat; ordinary Qi can lose more through alignment and temperature.
A worn phone battery needs less energy to show 100%, but it also runs for less time. Comparing current-health charges with new-battery-equivalent energy avoids a misleadingly high count.
Static data · no runtime API
Phone data and sources
Manufacturer and regulatory sources come first. When official capacity is unavailable, only an attributed secondary value or clearly marked estimate is used. Each selected model shows its source and verification date.
FAQ
Power bank charge FAQ
How many times can a 10,000mAh power bank charge a phone?
It depends on the phone battery and charging method. A 5,000mAh phone does not simply receive two full charges because voltage conversion, the cable, and the phone charging circuit all lose energy. Select a model and method above to see conservative, typical, and favorable estimates.
How many times can a 20,000mAh power bank charge an iPhone?
Different iPhone models store different amounts of energy, so there is no single charge count. Select the exact model and wired, Qi2, or Qi charging to include battery health and realistic losses.
How many times can a 20,000mAh power bank charge a Galaxy phone?
Galaxy S, A, and Z batteries vary widely by model. Search for your model to calculate from its recorded capacity, or enter the battery manually when a regional model is not listed.
What size power bank do I need for two phone charges?
Choose the required-capacity mode and enter two charges. The calculator reverses the charging losses and reports both the minimum estimate and the smallest common capacity tier that is not too small.
Does wireless charging reduce the number of charges?
Usually. Coil alignment and heat can make wireless charging less efficient than a cable. Qi2 and ordinary Qi use different planning ranges, but the real result still varies with alignment, case, and temperature.
Are multiple ports or pass-through charging included?
Not automatically. Output sharing, pass-through efficiency, and thermal limits vary by product, so applying one checkbox penalty would create misleading precision. If the manual provides simultaneous-output or efficiency data, enter it under Custom efficiency; otherwise plan with the conservative result.
Why can a worn phone battery show more full charges?
A worn battery needs less energy to move its display from 0% to 100%, but it also provides less runtime. The calculator therefore separates displayed full charges at current health from new-battery-equivalent energy.
Where can I find a power bank's rated output capacity?
Check the rear label or manual for Rated capacity or a 5V mAh figure. Because this value already reflects part of the internal conversion loss, rated-output mode does not apply that loss a second time.
What if my iPhone or Galaxy model is not listed?
Use Other phone / manual entry and provide mAh or Wh. Models before 2018 are outside automatic coverage, and regional names with the same verified battery may be consolidated under one record with aliases.