Trying to lose weight. How much cardio?

Im trying to lose some weight. Since i started lifting i never did any cardio. My strength has gone up but its time to feel better about myself. My gut has got to go. Its not "HUGE" but its there. And being cut and having a flat stomach makes you look SOOOOOOOOOOOO much better. Right now im 225lbs with about 22%bf, which was taken on a scale by a doctor so im not sure if its really accurate. But its probably close. Im not sure how much cardio to do. Today i got up and ran 20 min of hitt cardio, then lifting in the afternoon. Is 3 times a week good of the 20min? Everyother day?
Thanks alot.

you are probably right there. I would probably bump it to 30 minutes.

Try to gauge how much calories you are burning, your heart rate etc.

also doing a good job in keeping weights and cardio seperate.