The common belief that one year equals seven dog years is outdated. Today doctors use other factors, including the pet's weight and breed and size, to estimate their age in human years. Also environment plays an important part in calculating age, such as indoor pets typically live longer than outdoor pets. Below are two charts to help you determine you pets age in human years. The average life expectancy of a schnauzer is about 15 years. They show little signs of aging until later in life.
| Human years | 8 months | 1 year | 2 years | 5 years | 7 years | 9 years | 11 years | 13 years | 15 years |
| Canine years | 13 years | 16 years | 24 years | 32 years | 44 years | 52 years | 60 years | 68 years | 76 years |
| Small dogs less than 20 pounds | 9 to 13 years |
| Medium dogs 21 to 50 pounds | 9to11.5 years |
| Large dogs 51 to 90 pounds | 7.5 to 10.5 years |
| Giant dogs over 90 pounds | 6 to 9 years |
The charts above are only a guide. Please do not become alarmed with this chart. They are only guidelines to help determine when an animal becomes geriatric.
