Charring rate of wood is affected by density and moisture content of wood, heat flux and oxygen concentration of the surrounding air. A simplified model for charring of wood is presented as well as experimental charring rate results for some thermally thick wood species and wood products. The charring model can be used to calculate with ease and comparatively high accuracy relative changes in charring rate when any of the parameters describing the material or the surrounding conditions changes. Also the in practice important effect of moisture is taken into account in the calculations. Results given by the model are in good agreement with experimental data.