In 2008, Shina Tan derived a number of universal relations for an interacting Fermi gas with short-range, or contact, interactions [1–3]. These relations are very powerful because they connect microscopic quantities, such as the momentum distribution of the fermions, to macroscopic quantities, such as the total energy of the system. Furthermore, the relations are universal in that they do not depend on the details of the interparticle potential that gives rise to the interaction, nor do they depend on the state of the system, which could be an exotic Fermi superfluid, a normal Fermi liquid, or even a simple two-body state such as a diatomic molecule composed of two fermionic atoms. At the heart of the universal relations is a single quantity, which Tan termed the contact. The contact is defined as the amplitude of the high- k tail of the momentum distribution n ( k ), which was previously predicted to scale as 1 /k 4 for an interacting Fermi gas [7]. Remarkably, it can be shown that the contact encapsulates all of the many-body physics [6]. Therefore, it is predicted that by measuring this tail of the momentum distribution and then applying universal relations, one could determine many other properties of the system. Two recent papers report the contact for a strongly interacting Fermi gas, extracted from photoassociation measurements [5, 8] and inelastic Bragg spectroscopy [9] and compare the results with theoretical predictions for the BCS- BEC crossover. Here, we present a series of measurements that not only measure the contact in the BCS-BEC crossover with two different techniques, but moreover test the Tan relations experimentally by comparing measurements of both microscopic and macroscopic quantities in the same system. Our results directly verify the universal relations by exploiting the fact that while the value of the contact depends on the many-body state and on parameters such as temperature, number density, and interaction strength, the universal relations do not. Our measurements are done in an ultra cold gas of fermionic $^{40}$K atoms confined in a harmonic trapping potential. We cool the gas to quantum degeneracy in a far-detuned optical dipole trap as described in previous work [10]. The trap is axially symmetric and parameterized by a radial trap frequency, which varies for these data from ω$_{r}$ = 2 π · 230 to 2 π · 260 Hz and an axial trap frequency, which varies from ω$_{z}$ = 2 π · 17 to 2 π · 21 Hz. We obtain a 50 / 50 mixture of atoms in two spin states, namely the | f, m$_{f}$ 〉 = | 9 / 2 , − 9 / 2 〉 and | 9 / 2 , − 7 / 2 〉 states, where f is the total atomic spin and m$_{f}$ is the projection along the magnetic-field axis. Our final stage of evaporation occurs at a magnetic field of 203.5 G, where the s -wave scattering length, a , that characterizes the interactions between atoms in the | 9 / 2 , − 9 / 2 〉 and | 9 / 2 , − 7 / 2 〉 states is approximately 800 a$_{0}$ , where a$_{0}$ is the Bohr radius. 2