Usually after every feed or every 5–10 minutes during a feeding if they’re gassy or prone to spitting up. Breastfed babies sometimes need less burping, but every baby is different.
Try upright positions: over-the-shoulder, sitting on your lap, or lying across your knees. Sometimes a burp takes 30 seconds. Other times you’ll feel like you’re winding a jack-in-the-box that never pops.
And if you get nothing? That’s okay too. Just don’t stress—burping isn’t a perfect science.