A calibration of the TOPEX/POSEIDON and ERS 1 altimeters has been undertaken using altimetry across the English Channel. Data from the tide gauge installed at Newhaven and the satellite laser ranger at Herstmonceux were used in conjunction with local models for the geoid, ocean tide, and storm surge to generate bias values at each subsatellite altimetry point. A range bias value of -17.3 cm was generated for the NASA TOPEX altimeter relative to the four-parameter sea state bias model calculated by Gaspar et al. <1994>. The corresponding value for the Centre National d'Etudes Spatiales (CNES) POSEIDON solid state altimeter was -0.3 cm. The impact of other parameterizations for the sea state bias on the altimeter bias is studied. The derived results are in close agreement with results from the NASA calibration campaign at Harvest oil platform near California and the CNES experiment at the Italian Lampedusa island. The bias derived for ERS 1 was -39.3 cm relative to an Aston-derived single-parameter sea state bias model. ¿ American Geophysical Union 1996