Based on the best evidence as of the end of 2003, Dr. Catrine Tudor-Locke recommends the following:
Classification of pedometer-determined physical activity in healthy adults:
1) Under 5000 steps/day may be used as a "sedentary lifestyle index"
2) 5,000-7,499 steps/day is typical of daily activity excluding sports/exercise and might be considered "low active."
3) 7,500-9,999 likely includes some exercise or walking (and/or a job that requires more walking) and might be considered "somewhat active."
4) 10,000 steps/day indicates the point that should be used to classify individuals as "active".
5) Individuals who take more than 12,500 steps/day are likely to be classified as "highly active".
Source:
How Many Pedometer Steps Per Day Are Enough - Getting Enough Pedometer Steps Per Day