Corrections for the WD masses determined using zero temperature WD mass-radius relation (Nauenberg 1972) depending on the relative magnetospheric radius, r_m, with r_C = 10 or r_C = 1.25r_m if r_m ≥ 10 (solid curves). Corrections computed for non-rotating WDs are shown with dashed curves. Differences between WD masses found using hard X-ray observations (Suleimanov et al. 2019) and using optical methods are displayed for four IPs.