The search for Earth-like planets around Sun-like stars and the evaluation of their occurrence rate is a major topic of research for the exoplanetary community. Two key characteristics in defining a planet as Earth-like are having a radius between 1 and 1.75 times the Earths radius and orbiting inside the host stars habitable zone; the measurement of the planets radius and related error is however possible only via transit observations and is highly dependent on the precision of the host stars radius. A major improvement in the determination of stellar radius is represented by the unprecedented precision on parallax measurements provided by the Gaia astrometry satellite. We present a new estimate of the frequency of Earth-sized planets orbiting inside the host starss habitable zones, obtained using Gaia measurements of parallax for solar-type stars hosting validated planets in the Kepler field as input for reassessing the values of planetary radius and incident stellar flux. This updated occurrence rate can usefully inform future observational efforts searching for Earth-like system in the Sun backyard using a variety of techniques such as the spectrograph ESPRESSO, the space observatory PLATO and the proposed astrometric satellite Theia.
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