Many students ask this question and with good reason. Learning guitar is a journey and although the learning never stops there is usually a destination of some description in mind. When I was a teen my first destination was Stairway to Heaven. Along the way new destinations will arise but for most of us guitarists there is a song or riff or sole we desire to be able to play.
"Are we there yet?"
Now as with any journey it doesn't take long before we start wondering how long it will take to arrive. In my early years of learning I would at times ask the question but no one really offered a reasonable answer. Most responses were vague at best. For example they might respond by saying "It's all about patience" or "Keep working hard and you'll get there". When my own students began asking me the same question I decided to go looking for a different answer.
Takes 2 years of 30 minutes a day on average
I first decided that to measure I needed some kind of measuring stick so I created levels which included what I called the 7 essential skills. I than worked how long it would take the average student to complete each level. This gave me a very clear measurement of what the average student could expect based on the amount of time invested in practice, age and previous musical experience. I discovered that if a student was consistent with their practice it would take about 2 years to reach a level that most people would regard as competent.
The first make or break year
I also discovered that students who stuck with guitar for at least a year had about a 90% chance of reaching the 2 year mark. In other words students who could stay committed for a year were very unlikely to give up. In fact it was a sliding scale in the first year. I found that just by telling my students this fact from the start increased their chances of success. They now knew that their chances of success increased with every passing month. This gave them clarity and hope especially during those times when they began to doubt themselves. As they say, knowledge is power.