Objectives: Despite disadvantages such as time-consuming and tedious to the user, planimetrie volumetry is considered to be the most accurate method for prostate volume determination. This study investigates the possibilities of formula-derived volume determination and reveals the best alternative to planimetrie volumetry. Methods: The prostate volume is calculated using prostatic dimensions (length, height and width) in four mathematical descriptions for prostate volume calculations. As reference, the planimetrie results obtained with 4 mm step size were used. Results: Compared to the results of planimetrie volumetry obtained with 4-mm intersection distance, the best results for volume determination with mathematical calculation were obtained with a formula describing a spheroid volume using half the mean of width, height and length as radius. Conclusion: Although planimetrie volumetry remains the most accurate method for prostate volume determination, the spheroid formula is the best alternative method for quick volume assessment with reasonable accuracy.