Abstract In medical facilities, pre-shielding calculations are essential when introducing new X-ray equipment to protect the staff from radiation. For computed tomography (CT), the dose length product (DLP) method is commonly used for shielding calculations. This method allows the evaluation of the dose at any wall position. This study proposed a cost-effective design for CT room shielding, adjusting the material thickness based on the operator’s exposure and the room’s environment. Scattered radiation was measured using an optically stimulated luminescence dosemeter. The calculated values were 2.0 to 7.5 times higher than the measured values inside the CT room, confirming the accuracy of the DLP method in estimating the actual dose. No scattered radiation was detected outside the CT room. This study demonstrates that the DLP method enables pre-installation shielding calculations that balance cost and safety.