Soil acidification causes a decline in soil health and productivity globally. To combat soil acidification, liming materials containing calcium or magnesium compounds capable of neutralizing soil acidity are commonly applied as amendments. Concrete, the most used synthetic material on Earth, has potential as a liming material. The objective of this research was to experimentally determine the calcium carbonate equivalency (CCE) of concrete to determine if it could be an effective liming material. A factorial experiment was conducted with concrete age and concrete fragment size as factors; the levels of concrete age were New (ca. 1 year old) and Old (ca. 100 years old), and the levels of concrete fragment size were 2-8 mm, 0.25– 2 mm, and <0.25 mm. Four replications of the six treatment combinations were tested using the Indicator Titration Method from ASTM C25-24 Section 33. Significant differences in CCE were observed between treatments of varying fragment sizes (New 2-8 mm = 56 ± 1.6%; Old 2-8 mm = 58±6.2%; New 0.25-2 mm = 64±4.7%; Old 0.25-2 mm = 69±3.0%; New < 0.25 mm = 71±1.9%;  Old < 0.25 mm = 74 ± 3.2%). No significant differences were found in CCE between different aged concretes. The CCE of concrete was estimated as the weighted sum of the CCE values of the individual concrete solid constituents, found to be 69%, which is comparable to the measured values for the two smaller fragment sizes. This study supports the notion that concrete has potential as a liming material and should be explored further as a material to combat soil acidification.