Your battery percentage is going to be: 100 / DesignCapacity * MaxCapacity Or, in the way that makes way more sense to me: MaxCapacity / DesignCapaci

Your battery percentage is going to be: 100 / DesignCapacity * MaxCapacity Or, in the way that makes way more sense to me: MaxCapacity / DesignCapacity * 100 Which, with your results, yields something to the effect of: 98.68% It's kind of (read: very) dirty looking, but you can get the same result with: echo $(ioreg -l -n AppleSmartBattery -r | grep MaxCapacity | awk '{print $3}') / $(ioreg -l -n AppleSmartBattery -r | grep DesignCapacity | awk '{print $3}') \* 100 | bc -l