Its hard time when SD card unable to format, this is a common error not only in android but also in other OS, if you are getting this type of error like unable to format sd card or need to format before use, this means something happened to your sd card, so the point is how to fix or format sd card which is not formatting in android phone.
Here I will shows two easy and free ways, but before do remember one thing this will delete all data from memory card, if you agree with this than continue (we have to comprise something for this), so just follow these easy two steps.
1. Remove SD Card from phone and attach to PC
2. Format as traditional method right click “Format” select “Fat32” and than “start” if this not fix try second step
3. Go to google type and search for “SD formatter” open the first link download the tool and make a setup
4. Open the sd formatter select “Drive” click on “option” select “Full (Erase)” than “ok” and “Format”
