Stand barefoot against a flat wall on a level floor
Keep your heels, back, and head touching the wall
Look straight ahead
Place a flat object like a book on top of your head
Mark the wall where the bottom of the object touches
Measure from the floor to the mark with a tape measure
Use a ruler or measuring tape for accuracy
Measure in the morning for the most consistent result
Repeat the measurement 2 to 3 times
Record the final measurement in feet and inches or centimeters