Knee

• Sitting on your bike (use a door frame or friend for support), extend one foot so that it's at the bottom of your pedal stroke. Position the seat so that your knee is still bent about 25 to 30 degrees.
  
  

Heel of Your Foot

• Another method is to set your pedal at the bottom of its stroke (again, using a door frame or friend for support), and set your heel on the pedal. With your heel on the pedal, the seat should raise your body to a height so that the leg is completely straight.
  
  

Pedal Action

• If your hips rock side to side while pedaling, your seat is too low and is minimizing your pedaling efficiency.
  
  

Ride

• The best way to check your seat height is to measure and then go for a ride. If you're bike requires it, bring an Allen wrench with you, or use the quick-release lever to make minute adjustments to the fit as you ride.
  
  

Seat Itself

• Pay attention to how your seat is adjusted; nose up or down and back or forward. These details can also affect how the seat height feels for your body overall.