1. Bachelor's degree: Typically takes four years.
2. Master's degree (optional but often recommended): Typically takes one to two years.
3. PhD coursework and research: This can vary depending on the field, but generally takes around three to five years.
4. PhD dissertation and defense: This can take anywhere from one to three years.
So, in total, it usually takes around eight to ten years of full-time study and research to complete a PhD. However, this timeline can be shorter or longer depending on individual circumstances and research progress.