In this study, a comparison was held among the Stokes, Hotine and Deflection-geoid formulae
for gravimetric geoid modelling in Egypt, regarding the resulting statistical geoid features and
accuracies. For this purpose, relevant 2' x 2' grids of gravity anomalies, graviv disturbances and
vertical deflection components were input, yielding 2' x 2' detailed geoid models. The comparison
showed that the Stokes and Hofine methods yielded practically the same geoid features and
accuracy. The Deflection-geoid technique showed different geoid features and significalrtly better
accuracy. The comparison of the three geoid solutions at independent GPSLeveling control,
showed that the mean and standard deviation of discrepancies, pertaining to the Deflection-geoid
formula, are less by about 36% and 8%, respectively, compared to those relevant to the other two
formulae. Therefore, the vertical deflections are recommended as homogeneous input data lype in
gravimetric geoid detehination.