Add the tequila, triple sec, lime juice and agave into a large pitcher or carafe and stir to combine.
Refrigerate the pitcher or carafe until ready to serve.
When ready to serve, prepare the glasses. Add kosher salt to a shallow bowl. Rub the edge of the cocktail glass with the lime wedge then dip the glass in the salt.
Give the margarita a quick stir. Fill the glasses with ice and pour the margaritas over the top.