Acetabular reamers are a mainstay in the preparation of the acetabulum in total hip arthroplasty. Many surgeons, however, have noticed a discrepancy in the preparation of the socket and the reported size of reamers during this crucial phase of the procedure. A cross-sectional study performed by measuring a variety of sets of acetabular reamers was performed. The results showed that 17 of 21 sizes (81%) measured at least 2mm less than their reported size. Given that these differences beget unintended consequences, the industry may consider replacing or sharpening reamers already in use or even switching to a single-use reamer model.