WinAmtb is a Microsoft ® Visual Basic software developed for electron microprobe calcic amphibole analyses to calculate the pressure ( P ), temperature ( T ) and oxygen fugacity ( f O 2 ) conditions of amphibole-bearing alkaline to calc-alkaline rocks. The program estimates the structural formulae of calcic group amphibole analyses on the basis of IMA-04 nomenclature scheme, predicts cation site allocations and calculates stoichiometric H 2 O and ferric iron contents based on different normalization procedures. WinAmtb does not only estimate the P-T conditions of calcic amphiboles, but also the exchange reactions between amphibole and plagioclase pairs and amphibole-liquid equilibria. The program provides the user to type and load multiple amphibole, plagioclase and liquid compositions in the data entry section, to edit and load Microsoft ® Excel files in calculating, classifying and naming calcic amphiboles, and to store all the calculated parameters including amphibole cations, liquid cation fractions, plagioclase cations, thermobarometric and chemometric results in the Microsoft ® Excel file for further evaluations by the users.