A new quantitative model of production of the cosmogenic isotope 10Be by cosmic rays in the Earth's atmosphere is presented. The CRAC:10Be (Cosmic Ray induced Atmospheric Cascade for 10Be) model is based on a full numerical Monte-Carlo simulation of the nucleonic–electromagnetic–muon cascade induced by cosmic rays in the atmosphere and is able to compute the isotope's production rate at any given 3D location (geographical and altitude) and time, for all possible parameters including solar energetic particle events. The model was tested against the results of direct measurements of the 10Be production in a number of dedicated experiments to confirm its quantitative correctness. A set of tabulated values for the yield function is provided along with a detailed numerical recipe forming a “do-it-yourself” kit, which allows anyone interested to apply the model for any given conditions. This provides a useful tool for applying the cosmogenic isotope method in direct integration with other models, e.g., dynamical atmospheric transport.