Horse Years to Human Years Chart (The Only Chart You Need)

How Old Are Horses in Human Years?

Horses have a shorter lifespan than humans, and you may wonder how their age compares to ours. By knowing how horse years compare to human years, you can have a better understanding of the time of life your horse is in, whether they still have maturing to do, whether they’re in their prime, or whether they are ready for retirement.

How do horse years compare to human years? In the early stages of life, horses mature at a much faster rate compared to humans. However, once a horse reaches late adolescence at three years old, every horse year going forward will be equivalent to roughly  2.5 human years. To get a complete breakdown of horse years to human years, view the chart below.


As seen in the chart, there are certain stages in a horse’s life that tend to correspond with the same stage in human life. What should you expect out of your two-year-old horse? Well, according to the chart, your horse may have the mental and emotional state of a 13-year-old human. Keep that in mind when working with young ones! To get a more thorough breakdown of each stage of life a horse goes through, keep reading!

Horse Years to Human Years: Early Development in Horses

In a horse’s early years, they develop at an incredible speed, reaching 90% of their height at just one year of age. For this section, I’m going to consider a horse from one to three years of age in early development. 

Young Horse Mental State:

If you’ve ever worked with young horses, you have probably realized one thing…young horses have a very short attention span. If you’ve ever worked with young children, you’ve probably realized a similar thing…young children have a short attention span. 

Research shows that an adult horse has an attention span of just under 12 seconds long. That means for younger horses, you should consider it shorter. When it comes to training and asking a young horse to focus on a specific task, you should work no longer than 10-15 minutes each session. 

Just like young children, young horses can also absorb information and training very effectively. This is why it is recommended to start basic handling and groundwork with foals as soon as you can. To learn easy exercises to start with your young horses, visit my article How to Train a Young Horse: Everything You Need to Know.

Young Horse Physical State:

Three years old in horse years is equal to 18 years old in human years; so, within the first three years of a horse’s life, they go through as much growth and change as an 18-year-old kid. That’s a lot!

In the early years of a horse’s life, they are still developing and growing. A horse’s knee bones don’t fuse until they’re two years old. They also won’t reach their full height until about four years old. That being said, it’s important to keep this all in mind when you start bringing your horse along further in training.

There’s always been a debate about how young is too young to start a horse under saddle. In my personal opinion, I think it’s important to desensitize your horse to a saddle and the weight on its back early on so it’ll be more receptive when they’re older. I don’t fully start my horses under saddle until they are three years old, and even then, they will be brought along slowly. This is all in an attempt to not negatively impact the horse’s physical development.

Young Horse Care Requirements:

One of the biggest care requirements for young horses is mental stimulation. Young horses want to play, and it’s good for them to have another young horse friend or another adult horse that would be willing to play with them. My 11-year-old gelding still loves to play, and can get a bit wound up if he doesn’t have that outlet!

While sometimes grass is enough to sustain a young horse, consult with a vet to determine if you need to supplement your young horse’s feed. Young horses need to produce a lot of energy to effectively grow and develop. Feeding them a diet higher in protein can help meet that need.

Young horses may also require more frequent deworming, as they are more susceptible to certain parasites. Consult with a veterinarian to determine how often you should be deworming your horse.

Horse Years to Human Years: Maturity in Horses

Depending on the breed, horses don’t usually reach maturity until around four to six years of age. Certain breeds, like draft breeds and Arabians, are known to develop more slowly. 

Mature Horse Mental State:

At four years old, a horse is the equivalent of 20.5 human years. The horse can focus for longer periods of time and start to understand more concepts of training. Depending on the horse, four-year-olds can still be a bit rowdy and reactive to their environment until they are able to gain experience and confidence.

Mature Horse Physical State:

While most horses will have reached their full height at four years old, there’s still more development that will take place. From here, the horse will begin to fill out and build muscle. I look back at pictures from when my horse was four years old compared to when he had turned seven, and I’m always shocked at how much he looks just in his muscle tone! The saddle I used on my horse when he was four did not fit him when he turned seven. 

While at this stage in life, horses can work harder and reach new levels of training, it’s important to remember that they do have muscles to develop. Including muscle-building exercises in your training can help your horse fill out.  

Mature Horse Care Requirements:

By this stage in your horse’s life, you should have pinpointed any special requirements your particular horse has. One thing I will note is that while your horse is considered an adult at this point, it may still have some baby tendencies. While mares may mellow out in the pasture at this point, a lot of geldings will still like to play and get rowdy. Keep that in mind when finding pasture buddies for your horse!

Horse Years to Human Years: The Prime Years

When a horse is in their prime, they are fully developed both physically and mentally, able to meet higher demands and expectations in training and understanding. When you look at successful competition horses, many of them will be in the prime stage of their life.

Prime Horse Mental State:

A horse reaches their prime starting at 8 years old and lasting until they’re about 13. At this point, the horse is mentally developed. Their attention span will be longer than that of a young horse, and they’ll be able to focus more fully. 

Prime Horse Physical State:

In the prime of life, horses can be in the top physical state. All that being said, this state doesn’t just happen; gradual work still needs to be done to maintain and build muscle, stamina, finesse, and endurance. At this age, horses can develop muscles and physicality as much as they’ll ever be able to. For this reason, even the Olympics require a horse to be 8 years of age or older to compete.

Prime Horse Care Requirements:

Much of the care requirements for a horse in its prime will depend on the level at which they are being worked. If your horse is a performance horse training frequently and rigorously, they may require extra dietary supplements to help them produce energy. They’ll also require careful and thorough care of their body, as frequent intensive training can lead to injury if preventative measures are not taken.

A horse that lives a quieter life, being ridden but not worked at hard, won’t need as much meticulous attention.  

Horse Years to Human Years: Horses Reaching Middle-Age

While many horses are still active and able well into the middle of life, they will start to require more maintenance as they age. A horse is considered middle-aged from 14 to 19 years of age. This is equivalent to a human between 45 – 58 years old. This means there may now be some aches and pains, and it may be hard to get out of bed in the morning!

Middle-Aged Horse Mental State:

A middle-aged horse will still be as sharp as a horse in its prime. Once many horses reach middle age, they tend to mellow out and be less reactive to their environment. Middle-aged horses make great riding companions for beginner riders or a rider simply looking for a safe ride.

Middle-Aged Horse Physical State:

Depending on the horse, early middle-aged horses can still perform at the level of a horse in its prime. That being said, as the horse progresses through this stage in life, their workload and capacity will have to be reduced. Even if the horse isn’t showing any signs that they’re being negatively affected by the work, this is best for preventative measures in the future. 

Signs that a horse may not be able to handle the same workload as it used to can include the horse showing signs of fatigue during a workout, laziness, panting/out of breath, tripping, or even refusing to do an activity, like stopping at jumps.

Middle-Aged Horse Care Requirements:

A middle-aged horse will go through a lot of the same health changes as a middle-aged person. The area I notice the biggest difference in horses is their joints. Once a horse reaches the middle of life, their joint may be more sore and stiff as they suffer from arthritis. 

There are many things that can help in this area, from joint supplements to massages, to even joint injections. Keeping older horses on turnout where they can move around freely compared to being in a stall can also help. The best thing to do if you notice your horse starting to move more stiffly or have problems with their joints is to consult a veterinarian. 

Horse Years to Human Years: Senior Horses

Once a horse reaches 20 years old, the equivalent of 60 human years, they are considered a senior. At this stage in their life, horses are nearing the average lifespan of their species; and with that comes certain changes. 

Senior Horse Mental State:

A senior horse’s mental state may gradually decline as they continue to age. While many senior horses stay sharp, you may notice a change in behavior in some. Some may seem more cranky while others will be quieter and calmer. It’s important to be patient with senior horses and remember where they’re at in life and all that they’ve done to serve humans!

Senior Horse Physical State:

At some point, a senior horse will need to be retired from regular work. When the work is starting to impact their health negatively, it’s time to back off. That being said, regular easy walks around the field or arena can be good to help a senior horse maintain muscle tone and health.

You’ll notice your senior horse will have a harder time maintaining muscle and even weight. They’ll move more stiffly and may not want to run around with the younger horses like they used to!

Senior Horse Care Requirements:

Senior horses will require more care than your average horse. At this stage in their lives, senior horses may start to lose teeth and properly grind down forage. This can affect their ability to eat and maintain their weight. Feeding softer materials, like soaked alfalfa and chopped hay, may be a better option for them.

Light physical activity can do wonders in helping soreness, stiffness, and circulation. Avoid keeping older horses in a stall for long periods of time, as standing still can cause them to become stiffer. 

Many senior horses need supplements to their diet that will help them maintain their weight. Consult your vet to see what’s best for your horse.

Lastly, while no one wants to think about it, it’s important to make a plan for what you’re going to do when your horse passes away. For guidance on this topic, visit my article What to do When Your Horse Dies.

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Carmella Abel, Pro Horse Trainer

Hi! I’m Carmella

My husband and I started Equine Helper to share what we’ve learned about owning and caring for horses. I’ve spent my whole life around horses, and I currently own a POA named Tucker. You can learn more here.

Thank you for reading, and happy trails!

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