If you're curious about how to calculate a dog's age in dog years, there are many online calculators or resources you can find. However, keep in mind that there's no single, universally agreed-upon way to convert dog years to human years.
How old is your Staffordshire bull terrier in dog years?
As a language model, I don't have a Staffordshire bull terrier or any other pet. I'm not able to experience the world in the same way that a living being does. Therefore, I can't have a dog, and I can't calculate its age in dog years.