The objective of the current work was to use digestion coefficients from the Hill et al. (2008) model after parameterization by Feng et al. (2015; VT model) to calculate phosphorus (P) bioavailability (P_VT) of common feeds used in dairy production. Compared with the bioavailability calculated by the VT model, using the NRC (2001) P absorption coefficient of 0.64 for forages would underestimate the bioavailabilities of alfalfa hay, alfalfa silage, corn silage, grass hay, mixed mainly legume silage and western hay. For concentrates, using the NRC (2001) P absorption coefficient of 0.70 would overestimate the bioavailabilities of canola, corn grain, dry barley, soybean meal and whole cottonseed but underestimate bioavailability of high moisture corn. Two dairy rations were formulated using nutrient values from the NRC (2001): a standard diet which includes minimal byproducts and a byproduct diet which has reduced corn and soybean meal that was replaced with corn gluten feed, distillers grains, hominy feed and wet brewers grains. For each diet, total bioavailable P was calculated using availability values from the NRC (2001) and the VT models. Comparison of P balance (the difference between required and bioavailable P) for each diet was made using the 2 sets of bioavailabilities for a reference cow weighing 682 kg, producing 38.6 kg of milk/d (3.5% fat and 3.0% true protein, 100 DIM) and consuming 23 kg of DM/d yielding an absorbable P requirement of 59.4 g/d. The standard diet supplied 56.7 g and 53.5 g of bioavailable P per day using bioavailabilities from the NRC (2001) and VT models, respectively, resulting in a P balance of −2.72 and −5.9 g/d. The byproduct diet provided 75.75 and 78.47 g/d of bioavailable P yielding P balances of 16.4 and 19.1 g per day respectively using the 2 sets of bioavailabilities. Thus using P bioavailabilities for individual ingredients that were based on the VT model resulted in different calculated P balances by diet and would result in differing P feeding levels if used in a field setting.