Intravenous fluids are prescribed during anesthesia to replace pre-existing deficits and ongoing losses, thereby maintaining an effective circulating blood volume and tissue oxygen delivery. But too much fluid can lead to a positive fluid balance, delaying normal GI function, increasing pulmonary dysfunction and the risk of surgical site infection. This evidence-based lecture will help sort out the evidence about what dose of fluids should be delivered to optimize outcomes and help patients feel better faster.