How to do the calf stretch
Stand facing a wall, step one foot back and press the back heel into the floor while leaning toward the wall. Keep the back leg straight for the upper calf, then repeat with a bent knee for the deeper soleus.
How long to hold it
The most common recommendation for a static calf stretch is 30 seconds per side, repeated 4 times, with a short break to switch sides. That is exactly how this timer is pre-configured: press start and it counts every hold, tells you when to switch sides with a distinct sound, and gives you 20 seconds of rest after the final rep. Your eyes never leave the floor.
Common mistakes
Letting the back heel lift, pointing the back foot outward, and skipping the bent-knee version that reaches the soleus.
Why it's worth doing
Tight calves limit ankle dorsiflexion, which shows up as knees caving in squats and extra strain on the Achilles. Runners benefit most from consistent calf work.
About this timer
ExtendTimer is a free stretching timer with sound cues for every phase: a steady tick while you hold, a count-in when you switch sides, and an alert on your final rep. It works offline, installs to your home screen like an app, and needs no account. Routines of up to two stretches are free forever; Pro ($4.99/month or $29.99/year) unlocks unlimited routines and the full sound studio.