Horse Weight: All You Need To Know About Average Horse Weight

Knowing your horse’s weight is one of the simplest things you can do to protect their health. The average horse weight in the UK sits somewhere between 450 kg and 600 kg, but a Shetland pony may weigh under 200 kg while a Shire can tip the scales at more than a tonne.

Weight decides how much forage your horse needs, how much wormer or medicine they should get, and how much a rider can safely ask them to carry. For rescue and rehomed horses, it is often the first thing a vet checks.

This guide gives you a UK breed weight chart, a free tape-measure calculator, and clear advice on horse weight gain, weight loss, senior horses and horses with Cushing’s (PPID).

Quick Answer

Key Takeaways

• The average horse weighs 450-600 kg, but breed, height, age, sex and fitness all change the figure.
• You can estimate weight at home with the formula: heart girth (cm) x heart girth (cm) x body length (cm) divided by 11,900.
• A weight tape or formula only tells you how heavy a horse is; fat scoring tells you whether that weight is healthy.
• Healthy weight gain starts with more good-quality forage, then oil and low-starch conditioning feeds, never sudden large meals.
• Overweight horses should lose no more than 0.5-1% of bodyweight per week and should still get at least 1.5% of bodyweight as forage dry matter.
• Horses with Cushing’s (PPID) that need to gain weight need calories from fibre and oil while keeping sugar and starch low.
• Many UK equine bodies suggest rider plus tack should stay at or below roughly 15-17% of the horse’s weight.

What Is the Average Horse Weight?

The average horse weight for a typical UK riding horse is around 450-600 kg. According to Horse & Country’s height and weight guide, horses can weigh anything from about 300 kg to 1,000 kg depending on breed and size.

Height is the biggest single factor. A 16hh horse carries a larger frame than a 14hh cob, so it will usually weigh more even at the same body condition. Mares are often a little lighter than stallions and geldings of the same breed.

Workload matters too. A large UK study by Carroll and Huntington in the Equine Veterinary Journal found racing Thoroughbreds were noticeably lighter than non-racing Thoroughbreds of the same height and condition score. Fit, lean horses simply carry less fat.

Horse Weight Chart: UK Breeds

This horse weight chart covers breeds you are likely to meet on British yards, including native ponies. Use it as a starting guide, not a target. Individual horses can sit well outside these ranges and still be healthy.

Sources: breed ranges from Horse & Country; Shire figures from the Shire Horse Society standard as summarised on Wikipedia.

Shire Horse Weight

The Shire is a British draught breed and one of the heaviest horses in the world. Adult Shire stallions and geldings usually weigh 850-1,100 kg, and there is no set weight standard for mares. Britannica notes stallions often stand a little over 17hh and weigh around 900 kg.

The Shire Horse Society breed standard asks for stallions of at least 17hh (173 cm) at maturity. Because of their size, Shires need far larger feed rations and wormer doses than an average riding horse, so weighing them accurately matters even more.

The heaviest horse on record was also a Shire. Guinness World Records lists a 19th-century gelding called Sampson, bred in Bedfordshire, who stood 2.19 m tall and was said to weigh about 1,524 kg.

Race Horse Weight

A mature Thoroughbred racehorse usually weighs around 450-500 kg. A long-running study of over 600,000 race-day weigh-ins, published in BMC Veterinary Research, found fully grown racehorses averaged about 490 kg for colts, 480 kg for geldings and 465 kg for fillies and mares. That data comes from Japanese racing, but British-trained Thoroughbreds fall in a similar range.

In British racing, “weight” more often means the weight a horse carries. The British Horseracing Authority set the minimum riding weight on the Flat at 8 stone, and published weights were later raised by 2lb across the board. Jump horses carry more. In the Grand National, the top weight is capped at around 11st 12lb.

Retired racehorses often change shape once they leave training. If you have taken on an ex-racer, our guide to horse care for beginners is a good place to start.

How Much Does a Foal Weigh?

As a general rule of thumb, a healthy foal weighs roughly 10% of its dam’s bodyweight at birth. A 500 kg mare would therefore be expected to have a foal of around 50 kg.

Maiden mares often have slightly smaller foals. A foal that is much lighter than 10% of the mare’s weight may be premature or unwell, so call your vet straight away.

Horse Weight Calculator: How to Weigh Your Horse at Home

Most owners do not have a weighbridge. The good news is you can estimate weight well with a normal tape measure and a simple formula developed in the UK by Carroll and Huntington.

The Formula

Weight (kg) = heart girth (cm) x heart girth (cm) x body length (cm) / 11,900

1. Stand your horse square on flat, level ground.
2. Measure the heart girth: run the tape around the body just behind the withers and elbows, and read it as your horse breathes out.
3. Measure body length: from the point of the shoulder to the point of the buttock in a straight line.
4. Multiply the girth by itself, multiply by the length, then divide by 11,900.
5. Repeat two or three times and take the average.

Worked example: a horse with a 190 cm girth and a 170 cm body length weighs about 190 x 190 x 170 / 11,900 = 516 kg.

Quick Calculator Table

Weight Tape vs Weighbridge

A weighbridge is the most accurate option, and some UK feed companies run portable weighbridge days at yards and shows. Weight tapes are handy for spotting changes but can vary between brands, and they work less well on very small ponies and heavy breeds. World Horse Welfare recommends tapes with both a horse and a pony side, and suggests checking weight and fat score every fortnight.

Why Your Horse’s Weight Matters

• Feeding: Daily forage and feed rations are worked out as a percentage of bodyweight.
• Worming and medicine: Under-dosing helps worms become resistant. A survey reported by Horse & Country found 44% of owners asked did not weigh their horse before worming. See our guide to deworming your horse.
• Health: Weight changes are an early warning sign for dental problems, worms, PPID and other illness. Read about common horse diseases.
• Riding: A horse’s weight helps you judge how heavy a rider they can comfortably carry.
• Transport: You need to know what your horse weighs to stay within your trailer or horsebox limits.

Is Your Horse a Healthy Weight? Fat Scoring Explained

A number on a tape does not tell you whether your horse is too fat or too thin. For that, you need to fat score (also called body condition scoring) by feeling for fat over the neck, back, ribs and hindquarters.

UK owners usually use either the 0-5 scale or the 1-9 Henneke scale. World Horse Welfare suggests the 0-5 system is easier if you are new to it. The British Equine Veterinary Association weight management plan gives an ideal score of 2.5-3 out of 5 for most horses.

Excess weight is a bigger problem in the UK than many owners realise. A study of 792 vet-registered horses and ponies led by the Animal Health Trust found 31% were obese, and native breeds and cobs were at higher risk.

Horse Weight Gain: How to Help a Thin Horse

Before changing the diet, ask your vet to check why your horse is losing condition. World Horse Welfare lists poor diet, worm burden, dental problems and Cushing’s/PPID as common causes of being underweight.

Step 1: Feed More Good-Quality Forage

Forage should always be the base of a weight gain plan. If a horse is not eating enough fibre, Your Horse’s nutrition experts warn that weight gain is almost impossible however much hard feed you add. Offer good hay or haylage freely, and make sure timid horses are not being pushed off the haynet. Turnout on good grazing can help too; see our guide to keeping a horse in the meadow.

Step 2: Add Slow-Release Calories

Choose a conditioning feed with a digestible energy of at least 11-12 MJ/kg. Feeds based on unmolassed sugar beet, alfalfa and linseed or vegetable oil add calories without making most horses fizzy. This is gentler on the gut than large meals of cereal-based mix. For background on cereal feeds, read our guide to sweet feed for horses.

Step 3: Feed Little and Often

Split hard feed into several small meals rather than one or two large ones. Make any change gradually over 1-2 weeks so the gut bacteria can adjust.

Step 4: Keep Up the Routine Care

Book regular dental checks, use faecal egg counts to guide worming, and keep your horse warm and comfortable in wet UK winters so they are not burning calories just to stay warm.

How to Make a Horse Gain Weight Quickly (Safely)

There is no safe shortcut. Feeding a thin horse large amounts of feed at once can cause colic, laminitis or, in a starved horse, a dangerous condition called refeeding syndrome. Kentucky Equine Research advises that rescued, severely underweight horses may take three to six months to return to normal weight.

For a mildly underweight horse, the fastest safe route is:

• Free access to good forage, all day and night if possible.
• A high-calorie, low-starch conditioning feed, introduced slowly.
• Added oil or micronised linseed for concentrated calories.
• Small, frequent meals rather than big buckets.
• A vet check to rule out teeth, worms, ulcers or PPID.

To put this in numbers, raising a 500 kg horse by one point on the 9-point condition scale takes roughly 16-20 kg of gain, according to Purina’s equine nutrition team. That usually means weeks, not days.

If you have rescued a very thin horse, contact your vet before feeding anything beyond small amounts of hay, and if you are worried about a neglected horse, report it to World Horse Welfare.

Horse Weight Gain Feed and Supplements

Horse weight gain supplements are best seen as a top-up to a forage-first diet. They will not fix a horse that is not getting enough fibre. The main types you will find at UK retailers such as Pets at Home, VioVet and local feed merchants are listed below.

Examples of widely sold UK conditioning feeds include Dengie Alfa-A Oil and Spillers Digest+ Conditioning Cubes, both featured in Horse & Rider’s feeding for condition guide. Prices vary by retailer and bag size, so check before you buy.

One common myth: soaked sugar beet is mostly water. Spillers’ nutritionist told Horse & Hound it is around 80% water once soaked, so it adds fewer calories per scoop than many owners think.

Senior Horse Weight Gain Supplement and Feeding Guide

Older horses often lose weight because their teeth wear down and their digestion becomes less efficient. Do not assume weight loss is “just age”. Check these first:

• Teeth: Equestrian Trade News notes older horses may need more frequent dental checks. Signs include quidding (dropping balls of chewed food), slow eating and whole grains in droppings.
• Worms: Your Horse advises regular faecal egg counts, as veterans have lower resistance to worms.
• PPID: Cushing’s is common in older horses and can cause muscle and weight loss.

For a senior horse that struggles to chew, the best weight gain approach is usually:

• Short-chop fibre or chaff in place of some long hay.
• Soaked veteran cubes or a quick-soaking fibre mash. If your horse cannot manage hay at all, a full forage replacer fed in several meals a day.
• Added oil or micronised linseed for extra calories.
• A senior conditioning supplement or balancer to cover vitamins, minerals and quality protein for topline.

Soak feed fresh each day and add a little warm water in cold weather, as many older horses refuse cold, wet mashes. Our article on the lifespan of a horse covers more on caring for older horses.

What to Feed a Horse with Cushing’s to Gain Weight

Cushing’s disease, properly called pituitary pars intermedia dysfunction (PPID), often affects older horses. Some become overweight, while others lose muscle and condition. Because PPID raises the risk of laminitis, weight gain has to come from the right kind of calories.

• Keep sugar and starch low: Avoid cereal-based and molassed feeds, and choose bagged feeds clearly labelled low in sugar and starch.
• Test or soak hay: Baileys Horse Feeds recommends forage with under 10% water-soluble carbohydrate (sugar), soaking hay if needed, and carefully managed grazing.
• Use fibre and oil for calories: Low-starch, high-calorie conditioning feeds, unmolassed sugar beet and alfalfa are useful bases.
• Add oil steadily: Kentucky Equine Research suggests up to 120-240 ml of vegetable oil twice daily for thin PPID horses, alongside forage, introduced gradually.
• Feed small meals: Several small low-starch meals keep blood sugar and insulin steadier than one big feed.
• Work with your vet: Many PPID horses are prescribed pergolide, and getting the condition under control often makes weight gain much easier.

Avoid cereal-heavy mixes and molassed feeds. If your horse has had laminitis or has insulin problems, speak to your vet or a qualified nutritionist before increasing calories.

Horse Weight Loss: How to Slim Down an Overweight Horse

Many UK leisure horses get more calories than they need from grass alone. World Horse Welfare’s top tips include not crash dieting, controlling grass intake, reconsidering rugs and walking more.

How Fast Should a Horse Lose Weight?

Aim for 0.5-1% of bodyweight a week, according to Equestrian Trade News. For a 500 kg horse that is 2.5-5 kg a week, the same range given in Dengie’s weight management guide. At that pace, losing 50 kg takes roughly 10-20 weeks.

Practical Weight Loss Steps

• Never starve: Feed at least 1.5% of bodyweight per day as forage dry matter. For a 500 kg horse, that is around 7.5 kg of dry matter, or roughly 8-8.5 kg of hay as fed.
• Weigh all forage: Use a hanging scale instead of guessing by the haynet.
• Soak hay: Soaking reduces sugar content; mixing in clean straw can lower calories further.
• Slow eating down: Small-holed or double haynets make the ration last longer.
• Restrict grass: Use strip grazing, a track system or a grazing muzzle.
• Drop the hard feed: Replace mixes with a low-calorie balancer so vitamins and minerals stay covered.
• Increase exercise: Brisk walking and hill work burn fat well.
• Rethink rugs: Letting your horse use some energy to keep warm in winter helps natural seasonal weight loss.

Horse Weight Limit: How Much Weight Can a Horse Carry?

The old “20% rule” says a horse can carry 20% of its own bodyweight, including tack. UK research suggests a lower figure is kinder. In a pilot study led by Dr Sue Dyson at the Animal Health Trust, riders averaging around 16.7% or more of the horse’s weight caused significant signs of discomfort, although the lameness seen was temporary.

UK organisations have responded. Retraining of Racehorses uses a limit of 17% for rider plus all tack in its competitions. Vet Times points out that fitness, conformation, saddle fit and rider balance all change what a horse can comfortably carry.

Rider Weight Guide

Figures include saddle and tack, which often weigh 6-10 kg together.

Weight Records and Curiosities

• Heaviest horse: Sampson, a Shire gelding bred in Bedfordshire, said to weigh about 1,524 kg.
• Other heavyweights: Percherons typically weigh 850-950 kg and Ardennes horses up to around 1,000 kg, according to Horse & Country.
• Lightest UK breed: The Shetland pony, at around 180-200 kg, is the lightest native breed in our chart.
• Strongest for size: Shetland ponies are famously strong for their height, but that does not mean they should carry heavy riders.

FAQs

How much does an average horse weigh in the UK?

Most UK riding horses weigh 450-600 kg. Native ponies can weigh 180-450 kg, and heavy breeds such as Shires and Clydesdales often weigh 700-1,100 kg.

How much does a Shire horse weigh?

Adult Shire stallions and geldings usually weigh 850-1,100 kg. Mares have no set weight standard but are often a little lighter.

How much does a racehorse weigh?

A fully grown Thoroughbred racehorse usually weighs around 450-500 kg. Colts and geldings tend to be slightly heavier than fillies and mares.

How accurate is a horse weight calculator or weight tape?

A tape-measure formula or weight tape gives a useful estimate, but it can be out by several kilograms. A weighbridge is the most accurate option. Use the same method each time so you can track changes.

How can I make my horse gain weight quickly?

There is no safe instant fix. Give more good-quality forage, add a low-starch conditioning feed and oil gradually, feed little and often, and ask your vet to check teeth, worms and PPID. Visible gains usually take several weeks.

What should I feed a horse with Cushing’s to gain weight?

Feed calories from fibre and oil while keeping sugar and starch low. Good options include low-starch conditioning feeds, unmolassed sugar beet, alfalfa and added vegetable oil, alongside tested or soaked hay. Always check the plan with your vet.

How much weight can a horse carry?

As a guide, rider plus tack should stay at or below about 15-17% of the horse’s bodyweight. For a 500 kg horse, that is around 75-85 kg in total. Fitness, conformation and saddle fit also matter.

Related Articles

• Deworm Your Horse: Dewormed In Which Season?
• 6 Most Common Horse Diseases
• Lifespan of a Horse: Age, Food, and Health
• Sweet Feed for Horses: A Beginner’s Guide
• 4 Horse Care Tips For Beginners

Conclusion

Most horses weigh between 450 and 600 kg, but the right weight for your horse depends on breed, height, age and workload. Weigh or tape your horse every couple of weeks, fat score at the same time, and you will spot problems long before they become serious.

If your horse needs to gain weight, build the plan on forage first, then add oil and low-starch conditioning feeds slowly. If they need to lose weight, cut calories gently, never starve, and add more walking. Horses with PPID and seniors need extra care, so involve your vet early.

Thinking of giving a rescue horse a second chance? UK charities such as World Horse Welfare rehome horses with full support, including help getting them to a healthy weight.

Medical Disclaimer: This article is for informational purposes only and does not replace professional veterinary advice. Always consult your veterinary surgeon or a qualified equine nutritionist before changing your horse’s diet, medication, or care routine.