Door-opening forces are very important in smoke control because people cannot escape the threats of fire and smoke when door-opening forces are excessive. Thirty-seven years ago, the equation for calculating the opening force of a hinged door with a door knob in a smoke control system was developed. This equation has been used extensively for design and acceptance testing of smoke control systems. Door hardware has changed considerably due to concerns about accessibility. Today, most doors in buildings have lever handles and some have panic hardware. Analysis of how people use their hands is straightforward with door knobs, but it is more complex with lever handles and panic hardware. This paper adapts the old equation for today's hardware and presents a new equation for pivoted doors. The impact of lever handles and panic hardware on design and testing of smoke control systems is discussed.