In general, horses reach approximately 90-95% of their full height by the age of 2 years. By following proper nutrition and care, a horse can potentially gain an additional 5-10% of its height by the age of 4.
Considering your horse's current height and age, it's possible that it may still experience some growth. The rate and amount of growth can vary depending on the individual horse. As a rough estimate, you can add approximately 1-2 inches to your horse's current height at the withers for every year of growth up to the age of 4.
It's important to remember that these projections are just estimates, and the actual growth and development of your horse may differ. Regular veterinary check-ups, proper nutrition, and exercise are essential for ensuring the healthy growth and overall well-being of your horse.