using Microsoft.JScript; // needs a reference to Microsoft.JScript.dll using Microsoft.JScript.Vsa; // needs a reference to Microsoft.Vsa.dll // ... string expr = "7 + (5 * 4)"; Console.WriteLine(JScriptEval(expr)); // displays 27 // ... public static VsaEngine _engine = VsaEngine.CreateEngine(); public static double JScriptEval(string expr) { // error checking etc removed for brevity return double.Parse(Eval.JScriptEvaluate(expr, _engine).ToString()); }