Bru Coffee: India's Beloved Instant Brew It's National Coffee Day, but it's important to keep track of how much caffeine goes into your body in a 24 hour period. For most adults, the FDA has cited 400 milligrams* a Perka Bartlett 24 oz. Double Wall, Stainless Steel Stacking Mug Custom Perka Amazon.com: 3 Pack Shot Glass Measuring Cup, Small Espresso Shot Glasses with Measuring Lines, Heavy Liquid Glass with Measurements for Barista (20 Incremental, 1 Ounce, 6 Teaspoons, 2 Tablespoons, 30ml, Black): Home & Kitchen