This article reports a method of calibrating a DISA miniature hot-wire probe in pressurized nitrogen. The experimental data spans all the three flow regimes from natural, through mixed, to forced convection. For these regimes, heat transfer correlations have been obtained which are sufficiently accurate to be used for calibration purposes. These correlations have been compared with the comparable results for wires of larger aspect rations. The effect of aspect ratio on heat transfer characteristics has been assessed.