Treat the result as a starting keyboard height
The estimate scales from total height, but arm, torso, leg, shoe, and chair proportions differ. Set the keyboard near relaxed elbow height, keep shoulders down and wrists neutral, then adjust the desk rather than forcing the body to match the number.
Measure the complete sitting and standing setup
For sitting, include chair height and whether the feet rest flat or on a footrest. For standing, include shoes, an anti-fatigue mat, desktop thickness, and any keyboard tray. Confirm that the desk reaches both positions without operating at an uncomfortable limit.