In general, a respiratory therapist in the US receives his or her total earnings ranging from between $37,671 – $68,309 per annum. The starting salary for a respiratory therapist is about $40,660 per annum, while an average respiratory therapist receives an annual salary of about $55,250 per year.espiratory therapist salary in UK. According to all salary survey, the average expected and median salary for a respiratory therapist in the United Kingdom is about £19,337 per year. An average hourly wage for a respiratory therapist is around £9.67 per hour.