Precise calculations of the properties of hadrons from first principles are needed to answer many important questions in high energy and nuclear physics. To deal with the strong interactions of quarks and gluons inside hadrons, the equations of quantum chromodynamics need to be solved on a space-time lattice using supercomputers. I perform lattice QCD calculations to facilitate searches for physics beyond the Standard Model in experiments such as LHCb, to predict the masses of as yet unobserved hadrons, and to better understand the complex structure of protons and neutrons