Li-Ion battery charging, termination current (ITERM)
I'm not an expert but the following article http://www.powerelectronics.com/mobile/proper-care-extends-li-ion-battery-life suggests:


  Selecting a charger that uses minimum charge-current termination (C/10 or C/x) can also extend battery life by not charging to 100% capacity. For example, ending a charge cycle when the current drops to C/5 is similar to reducing the float voltage to 4.1 V. In both instances, the battery is only charged to approximately 85% of capacity, which is an important factor in battery life.


To take one of your examples, you have a 1000mAh battery, you charge 'til you reach 180mA, that's approx C/5, thus approx 85% of capacity. Elsewhere I read that C/10 results in ~92% of capacity. I don't have a formula, though, sorry.