The potential of using NMR as a reference method for WHC measurement in porcine longissimus dorsi was investigated. The accuracy of NMR when measuring small water changes was assessed in a model system and in muscles. Visible/near infrared (Vis/NIR) and X-ray were used as potential online spectroscopic methods to assess WHC on 40 muscles. Drip loss and spin–spin relaxation were also measured. Calibration models were built using partial least squares regression (PLSR) with Vis/NIR or X-ray spectra as input and NMR or drip loss values as output. The slowest spin–spin relaxation time (T22) showed higher correlation with both Vis/NIR (View the MathML sourceRCV2 = 0.66) and X-ray spectra (View the MathML sourceRCV2 = 0.76) than EZ-DripLoss values, demonstrating NMR has potential as a reference method for WHC measurement. NMR was more robust against variation along the length of the muscle when compared to the EZ-DripLoss method.