We report a study of the CUORE sensitivity to neutrinoless double beta ($0 ubetabeta$) decay. We used a Bayesian analysis based on a toy Monte Carlo (MC) approach to extract the exclusion sensitivity to the $0 ubetabeta$ decay half-life ($T_{1/2}^{0 u}$) at $90%$ credibility interval (CI) -- i.e. the interval containing the true value of $T_{1/2}^{0 u}$ with $90%$ probability -- and the $3 sigma$ discovery sensitivity. We consider various background levels and energy resolutions, and describe the influence of the data division in subsets with different background levels. If the background level and the energy resolution meet the expectation, CUORE will reach a $90%$ CI exclusion sensitivity of $2cdot10^{25}$ yr with $3$ months, and $9cdot10^{25}$ yr with $5$ years of live time. Under the same conditions, the discovery sensitivity after $3$ months and $5$ years will be $7cdot10^{24}$ yr and $4cdot10^{25}$ yr, respectively.