Velocity estimation by coherency inversion provides a velocity-depth macro-model of the subsurface. The accuracy of this model is critical for imaging techniques such as depth migration and inversion. Therefore, the reliability of seismic interpretation is strongly dependent on the accuracy of the derived model. Uncertainties in the velocity and depth estimates for the model can be calculated using a combination of the response surface technique and the Dix equation. In the layer-stripping strategy, the method takes into account the local errors connected mainly to the current layer and the global errors connected to the derived overburden. Examples using synthetic and real data show that the coherency inversion produces accurate macro-models.