A set of unified formulas for prediction of wave overtopping rate at coastal structures have been derived by analyzing the CLASH database. The new formulas are applicable for vertical seawalls, smooth impermeable slopes, and composite seawalls with frontal mounds built with Tetrapods. The formulas are simple but cover the full range of water depth from the shoreline to deep water. The effects of the toe depth and the seabed slope on wave overtopping rate are duly incorporated in the formulas. Prediction performance of the new formulas is better than the EurOtop formula for both vertical walls and inclined seawalls.