It actually depends on the size of your glass. Wine has a serving size of approximately 4 or 5 ounces. Most wine glasses, however, usually serve approximately 10 ounces! Red wine tends to have about 106 calories in just a 5 ounce serving, but if you’re toasting with that 10 ounce glass, you’re taking in double at 212 calories. Having 2nd thoughts about that 2nd glass now?