A new method to perform X-ray absorption correction for spherical particles in quantitative energy-dispersive X-ray spectroscopy in the scanning transmission electron microscope is presented. An absorption correction factor is derived and simulated data is presented encompassing a range of X-ray absorption conditions. Theoretical calculations are compared with experimental data of X-ray counts from Au nanoparticles to verify the derived methodology. The effect of detector elevation angle is considered and a comparison with thin-film absorption correction is included.