Accurate determination of burn size significantly impacts both immediate management and long-term outcome. In the era of evidence-based medicine, the variability in TBSA% assessment shown by traditional methods may prove unacceptable and technology-aided systems become the “accepted standard.” The objective of this study was to push this scenario to the limit by investigating the accuracy and consistency of TBSA% estimations using a computer-aided tool. Five Laymen (health care–burn management naïve people) were trained on the handling of the technology-aided assessment tool Burn Case 3D© and asked to calculate TBSA% for 18 clinical pictures of burns with different patterns and sizes. Forty-four burn Professionals (senior burn surgeons, plastic surgery residents, anesthesiologists, emergency physicians, senior registered nurses) were provided the same pictures and assessed TBSA% using traditional paper-based tools (“Rule of Palm”; “[Wallace] Rule of Nines”; “Lund and Browder chart). The Laymen’s computer-aided calculations did not differ significantly (P > .05) from the senior burn surgeons’ estimations in 17 of the 18 cases. However, when comparing the Laymen’s TBSA% calculations with the whole group Professionals there were significant differences (P < .05) in (again) 17 of the 18 cases. Laymen’s calculations were also more consistent (mean SD, 0.95%). The Professionals showed a generalized significant overestimation of TBSA% as compared with the Laymen’s calculations (up to 198.5%). Innovative software provide a high potential to improve objectivity and quality of burn assessment in the future.