New puppies need 18-20 hours of sleep per day to support their development and growth.

Young adult dogs tend to sleep around 14 hours per day from ages 6 months to 2 years old.  

Most adult dogs sleep 12-14 hours per 24 hour cycle including naps and nighttime.

Older dogs often sleep more like 16 hours a day due to increased idling and restless nights.

Dogs tend to nap frequently during the day in short bursts - usually 30 minutes or less.

Dogs have REM and non-REM sleep cycles like humans, alternating every 10 minutes.

Dogs who get more exercise may require more sleep to recover compared to idle pets.