Following table shows a list of top VoIP services that provide cheap and even free pc to mobile calls to China. If you are looking for free calling, then Rynga, 12voip and smartvpoip are better options among several others. All these services offer free calls for a fixed period of time each time after you recharge your account.
Once free days are over, normal charges apply. If you do not make calls to China frequently, then these free services may not be best for you. In such case Easyvoip or voipdiscount.com world be a better option.
Here is the table with comparison of call rates for your reference>
|Service Provider||Call Rate Landline||Call Rate Mobile|
|Easyvoip.com (+ $0.039 con. fee)||$0.006||$0.006|