  We present results of modelling the bulk of the spectral energy distribution
(0.35 - 5 micron) for GJ406 (M6V). Synthetic spectra were calculated using the
NextGen, Dusty and Cond model atmospheres and incorporate line lists for H2O,
TiO, CrH, FeH, CO, MgH molecules as well as the VALD line list of atomic lines.
A comparison of synthetic and observed spectra gives Tef = 2800 +/- 100 K. We
determine M$_bol = 12.13 +/- 0.10 for which evolutionary models by Baraffe et
al. (2003) suggest an age of around 0.1 -- 0.35 Gyr consistent with its high
activity. The age and luminosity of GJ406 correspond to a wide range of
plausible masses (0.07 -- 0.1 Msun).
