Bath-type ultrasonic system still lacks fundamental assessment including thermal profile and power behavior, despite being regarded as more promising than probe-type ultrasonic for large-scale application. Therefore, this report aims to explore the power pattern in ultrasonic bath reactor using calorimetry method derived from cavitation-generated heat. Ultrasonic power and frequency were varied from 30-120 W and 25-60 kHz, respectively, within a cylindrical bath reactor containing one litre of deionized water. Temperature sensors were placed accordingly, and the temperature difference was recorded in interval for 30 minutes. Result shows that the temperature change was larger near the ultrasonic emitter and dissipated as distance increased, implying higher calorimetric power or active cavitation action close to the source. Calorimetric power was generally enhanced as higher ultrasonic power was supplied, while ultrasonic frequency provided slightly intricate effect. From hypothesis testing, only ultrasonic power was statistically significant from its p-value < 0.05 based on 95 confidence interval. © 2023,GMSARN International Journal. All Rights Reserved.