A Hermann tortoise is an excellent pet with its cute face and easy-going temperament. These tortoises are relatively simple to look after and feed. But how big do they typically get, on average, and what do you need to consider regarding their size? This is all you need to know.
So, how big does a Hermann tortoise get? The average adult Hermann tortoise can range from 5 to 8 inches long (13 to 20cm). Some tortoises can reach as much as 11 inches (28cm) in length, with a weight of 7 to 9 pounds (3 to 4kg). Females tend, on average, to be about 12% larger than males. The eastern subspecies are typically larger than the western subspecies.
A Hermann tortoise usually doesn’t need a separate enclosure with a specific microclimate, and it can quite happily graze on what is growing in your backyard.
You do want to pay attention to the growth of your Hermann tortoise, though, to be sure that they are in good health.
With this in mind, let us now look at some other important considerations regarding their size, starting with their typical growth rate!
At What Age Is A Hermann Tortoise Fully Grown?
A Hermann tortoise grows very slowly: they aren’t considered to be fully grown until they’re about 10 years old.
As such, they are especially vulnerable to top predators such as foxes when they are young, as their shells don’t fully harden until 5 to 6 years of age.
If you have a Hermann tortoise hatchling, you won’t even know if you have a male or a female until your friend is about 6 to 7 years old!
At this age, males will have much larger tales, though females will be larger overall.
Females will develop a concave belly, while males won’t.
These tortoises have long adult lives: they can live up to 75 years of age or even longer in optimal conditions.
Use The Jackson Ratio
If you want to know whether your tortoise is at a healthy weight for its size, the best resource is the measurement known as the ‘Jackson Ratio.’
This ratio works out the relationship between your tortoise’s weight and their body length, which determines the ‘density’ of your friend.
The resulting density figure is usually between 0.16 and 0.23.
More information, including a handy Jackson Ratio calculating tool, is here.
It’s crucial to determine your tortoise’s weight to body length ratio in order for your friend to hibernate safely.
Like all animals who hibernate, tortoises need a certain percentage of body fat to sustain them while they sleep.
Hibernation in tortoises can last from several weeks to several months.
If, for example, your tortoise has a ‘density’ below 0.19, hibernation can be dangerous.
In these cases, you can ‘overwinter’ your tortoise instead.
Factors That Can Influence Growth Rate And Full Size
There are various factors that can influence the growth rate of your Hermann tortoise and its full size, including the subspecies, diet, and supplementation given.
Let us now look at each one a little more closely.
The Subspecies of Your Hermann Tortoise
If your tortoise is a member of the eastern subspecies, Testudo hermanni boettgeri, your tortoise’s total growth will be slightly more than those of the western subspecies.
The average adult size for eastern Hermann tortoises is about 7 inches for males and 8 to 9 inches for females.
Your tortoise will most likely grow to be a bit smaller if your friend is a member of the western subspecies, Testudo hermanni hermanni.
Average adult sizes are 5 inches for males and up to 6 inches for females.
Hermann Tortoise Diet
The right balance of food can ensure a healthy tortoise as well as influence their rate of growth.
A Hermann tortoise needs a low-protein, high-fiber diet with plenty of calcium.
Aim to feed your tortoise a mixture of:
- Carrots (the tops, too)
- Collard greens
- Curly kale
- Mustard greens
- Turnip greens
- Mulberry leaves
- Plantain leaves
Try to get organic greens and provide a mixture of wild and store-bought greens rather than relying exclusively on supermarket produce.
Greens and vegetables from stores are often lacking in minerals and fiber.
Wild greens are one of the best foods for your tortoise, as these plants have adapted naturally to survive in tough conditions.
As a general rule, stay away from lettuces, which are often nutrient-deficient.
Ask your vet if you are unsure what plants you have in your yard or which wild plants you can feed your tortoise.
You can also plant a selection of tortoise-friendly plants, which your friend will enjoy exploring and munching on.
Some people provide a Mazuri tortoise diet a few times a week.
Check with your vet first, but if you have any concerns about the development of hatchlings or nutritional deficiencies for females who have just laid eggs, supplementation could work for your pets.
While some tortoise owners sprinkle calcium powder on their pets’ food, you don’t need to do this.
In fact, it’s best not to force calcium on your tortoise: too much calcium can cause health problems.
If you are concerned about calcium levels in your pet, you can keep a supply of cuttlebone in the enclosure.
Your tort will nibble on it occasionally as needed – less worry for you.
How Much Space Does A Hermann Tortoise Need?
An average-sized Hermann tortoise needs a space or enclosure that is at least 4 feet by 4 feet, and the larger the better.
You might think that amount of space would seem daunting to a baby tortoise, but you’re better off setting up something that will accommodate your friend for life.
If you have several tortoises, you’ll definitely need a larger space so that they aren’t on top of each other.
There’s no such thing as too much space for a tortoise!
Tortoises are very active animals, so even if you have a large indoor space for them, they still need to be outdoors sometimes.
Your tort will really appreciate even just a few hours a day of fresh air and sunlight in warm weather, with the ability to graze.
Time outdoors will also help your tortoise absorb vitamin D naturally.
The better the conditions for your tortoise, the longer your friend will be with you: some Hermann tortoises can live to over 100 years in the right conditions.
When Your Hermann Tortoise Is Kept Outdoors
If your tortoise spends time outdoors, make sure any walls that define your tortoise’s living area are at least 18 inches high.
Otherwise, your friend might climb over to visit the neighbors!
Good materials to use are wood, concrete, or something else that’s solid. Although you wouldn’t think of tortoises as climbers, they will still try.
Be sure not to use transparent materials for the walls, or your tortoise will constantly try to get out to explore the ‘grass is greener’ theory!
You’ll also want to bury the walls a few feet underground.
Tortoises love to dig, so you don’t want them digging an escape tunnel – provide them with a few inches of earth or other organic materials that they can happily burrow into.
Set out some logs, mounds, branches, rocks, etc., for your friend to explore.
You want their enclosure to stimulate their curiosity – all animals need enrichment.
Tortoises are used to roam around on large parcels of land in the wild, so make sure they have plenty of room to wander. Exploration is part of their nature.
If you know you have foxes, raccoons, and other predators in your area, cover the top of the enclosure with a frame and a hardware cloth to protect your friend.
Be vigilant when your tortoise is outside.
When Your Hermann Tortoise Is Kept Indoors
If your tortoise lives mostly indoors, be sure to provide some natural sunlight for your pet every now and then.
You’ll still want to have an outdoor pen or enclosure that they can explore during the warmer months – this pen can be as big as you like.
For your pet’s indoor enclosure, the same rules apply to keeping things interesting.
Make the enclosure as big as possible, and put out branches, plants, rocks, and other items for your friend to explore.
Try to change things around regularly so that your friend doesn’t get bored.
You will probably notice that your tortoise will go to a corner of the enclosure and dig.
Digging is normal behavior, so remember to supply enough raw material for them to burrow to their heart’s content.
Keep the temperature of the enclosure in the mid-70s during the day and no lower than 65 degrees at night.
For baby tortoises, keep them warmer: nighttime temperatures should not go below 74 degrees.
Make sure you supply a basking spot for your pet at one end of the enclosure, as tortoises need UVB light to process calcium and synthesize vitamin D3.
Keep an eye on the humidity levels of the enclosure, as your Hermann tortoise comes from a semi-arid climate.
The enclosure will need to have enough room for a large, low bowl or a tray that your tortoise can climb into for regular baths.
Change the water every day, as tortoises will drink and defecate while in their bath!
Hermann tortoises reach a pretty average tortoise size when fully grown, at least in comparison to others like Russians.
They are slightly smaller than Red Foots, but considerably smaller, on the other hand than Sulcutas.
This makes them an ideal species to look after and raise.
And with the proper care, your Hermann tortoise will grow to be its optimum size and enjoy a long and happy life.
Oh, but before you go out and get one – be sure to consider the cost!
I am a practiced pet owner with decades of experience owning a number of different pets. I am also the main writer and chief editor here at Pet Educate; a site I created to share everything I’ve learned about pet ownership over the years and my extensive research along the way.