How Much Does a Donkey Weigh? Sizes, The Donkey Sanctuary Method and Healthy Weight

An adult donkey can weigh anywhere from about 100 to 500 kilograms (roughly 220 to 1,100 pounds), according to The Donkey Sanctuary, and the size class explains most of that range. In the Sanctuary’s own herd a standard donkey might weigh 165 kg (about 364 pounds) and a miniature 144 kg (about 317 pounds), while the Bureau of Land Management says wild burros in the American West average about 500 pounds, and The Livestock Conservancy puts American Mammoth Jackstock at 900 to 1,200 pounds. For a quick tape-based figure, the free donkey weight calculator works from two measurements and needs no account, but it uses a general formula that has not been validated on donkeys, so use it to track a trend rather than for a dose.

The more important point is how you get that number. Donkeys are not small horses: they carry fat in different places and have a different build, so horse weight tapes and horse formulas give the wrong answer. This guide shows the donkey-specific method The Donkey Sanctuary recommends, explains how our own calculator compares with it, and covers how to tell whether your donkey’s weight is healthy.

This page sits under the donkey species hub and covers donkeys of every size. If yours is a miniature, the mini donkey weight guide goes deeper on the small end. If you are still deciding whether to buy, see how much a donkey costs.

How much does a donkey weigh, by size?

In the United States donkeys are classed by height at the withers, not by breed, so weight follows the size class. The American Donkey and Mule Society (ADMS) lists the classes on its All About Donkeys page:

• Miniature Mediterranean: 36 inches and under.
• Standard: 36.01 to 48 inches (small standards 36.01 to 40, standards 40.01 to 48).
• Large standard: 48.01 to 54 inches for jennets and to 56 inches for jacks.
• Mammoth: over 54 inches for jennets and over 56 inches for jacks.

Here is what published sources say about weight in each:

Miniatures. The Donkey Sanctuary gives 144 kg (about 317 pounds) as an example of a miniature in its own herd, in its guide to monitoring your donkey’s weight. Minis have their own detailed pages on Creatures: mini donkey weight and miniature donkey size compared with standards.

Standards. The same Sanctuary page gives 165 kg (about 364 pounds) for a standard donkey in its herd. The Bureau of Land Management describes wild burros, which are standard-sized, as averaging 11 hands (44 inches) and about 500 pounds. The two figures are not in conflict so much as a reminder that “standard” spans a full foot of height. The American Standard donkey guide covers the class in detail.

Large standards and mammoths. The Livestock Conservancy, which lists the American Mammoth Jackstock as Critical on its conservation priority list, says the breed’s weight varies with height and ranges between 900 and 1,200 pounds. Our Mammoth donkey guide covers jackstock registration and care.

Foals and youngsters. The Donkey Sanctuary’s weight chart is for donkeys over the age of two, because a growing donkey’s proportions change. Track a youngster’s measurements over time and ask your veterinarian when you need a number for a young donkey.

Why horse weight tapes and formulas do not fit donkeys

Donkeys are a different species from horses, and the difference shows up in exactly the places a weight tape measures. The ASPCA’s guidance for donkey keepers (Four Tips for Healthy and Happy Donkeys) is direct: estimating a donkey’s weight “is not the same as estimating a horse’s weight,” because donkeys’ body shape and composition mean they carry their weight differently, so do not use a horse weight tape.

Three things go wrong when you use a horse method on a donkey:

1. Fat is stored differently. University of Georgia Extension notes that donkeys store fat differently from horses, which is why you judge their condition by feeling the neck, ribs and rump. The ASPCA adds that donkeys can develop hardened fat deposits that stay even when the donkey is underweight. A girth tape built around horses does not account for that.
2. The equations were built on horses. The relationship between girth and weight that a horse tape assumes was worked out on horses. Donkey researchers, from Morocco to Kenya, have built separate donkey equations instead of borrowing horse ones, and The Donkey Sanctuary uses its own chart.
3. The scale of error matters. Donkeys are small, and drug and feed decisions are made by weight. A few dozen pounds is a much larger share of a 350 pound donkey than of a 1,100 pound horse.

Ponies are a different story: they are horses, and horse-style formulas work for them within a known margin, as how much a pony weighs explains. For donkeys, the practical rule is: use a donkey method, use it the same way every time, and when an exact weight matters for a dose or an anesthetic, let your veterinarian weigh the donkey or estimate it themselves.

The Donkey Sanctuary method: height and heart girth

The Donkey Sanctuary, the UK donkey welfare charity, estimates weight from two measurements: height at the withers and heart girth. For donkeys over the age of two, you plot both measurements on its Donkey Weight Estimator chart (a free download on its weight monitoring page) and read off the estimated weight. The Sanctuary’s worked example: a donkey 104 cm tall with a heart girth of 122 cm should weigh 181 kg (about 399 pounds).

How to take the two measurements.

1. Stand the donkey square on level, firm ground, head up in a natural position.
2. Height: use a measuring stick with a crossbar and level at the highest point of the withers. A tape run over the shoulder reads high. The ADMS also uses withers height for its size classes, so this one number places your donkey in its class and goes into the weight chart.
3. Heart girth: run a soft tape around the body just behind the front legs and over the withers, snug but not tight, at the end of a breath out.
4. Record both, with the date, and repeat the same way next time. The Sanctuary recommends recording weight and condition monthly, so you can spot problems early.

A formula, if you prefer numbers to a chart. Researchers working with donkeys in Morocco, R. A. Pearson and M. Ouassat, published a donkey equation in the Veterinary Record in 1996 that uses heart girth and body length in centimeters. A 2020 study of Kenyan working donkeys in Veterinary Medicine International reproduces it as:

Weight (kg) = (heart girth^2.12 x body length^0.688) / 3801, for donkeys over 3 years, with heart girth and body length in centimeters and body length measured from the point of the elbow to the pin bone

It was built on working donkeys, so treat it as an estimate for a pet or companion donkey, but it is a donkey formula rather than a borrowed horse one.

How the Creatures donkey weight calculator compares

We want to be straight about our own tool. The free donkey weight calculator takes heart girth and body length and applies a general girth-squared-times-length formula (girth x girth x length, in inches, divided by 300). It is quick, free and consistent, but it is not The Donkey Sanctuary’s height-and-girth chart and it is not a formula developed on donkeys.

The two formulas also use different body-length landmarks, so they cannot simply be fed the same number. Pearson and Ouassat measure from the point of the elbow to the pin bone. Our calculator, like most horse formulas, measures from the point of the shoulder to the point of the buttock, which is a longer line on the same donkey.

Here is a hypothetical worked example, for a standard donkey with a 122 cm heart girth, to show how far apart the formulas can land:

• Pearson and Ouassat donkey equation, with an elbow-to-pin-bone length of 95 cm: about 160 kg (353 pounds).
• Creatures donkey weight calculator, with a shoulder-to-buttock length of 105 cm: about 144 kg (318 pounds), roughly 10 percent lower in this example.
• A typical horse formula (the same calculation divided by 330) with the same 105 cm: about 131 kg (289 pounds).

The 95 and 105 cm lengths are illustrative figures, not measurements of a real donkey, and how the two lengths compare varies from donkey to donkey. So the example shows that the formulas can disagree; it does not tell you how far off our calculator will be on your donkey. We have not tested the calculator against scale weights of donkeys, and we know of no published validation of it for donkeys, so we cannot give it a donkey accuracy figure. The note on the calculator page that “actual weight may vary by 5-10%” is a general note shared by all our weight calculators, not a figure measured on donkeys.

That is why we recommend using the calculator to track a trend (the same donkey, measured the same way, month after month), and using The Donkey Sanctuary chart or your veterinarian when you need a single number to act on. If the calculator and the chart disagree for your donkey, trust the chart.

Is my donkey a healthy weight?

A weight on its own does not tell you whether a donkey is fat or thin. You need a condition score beside it.

Score by feel, on the donkey scale. University of Georgia Extension explains in Donkeys: Not Just Another Horse (June 2026) that donkeys store fat differently from horses, so they are scored on a 1 to 5 scale instead of the horse’s 1 to 9, with 3 as the ideal. You have to feel the neck, ribs and rump: “It is very easy for a donkey to become overweight without it being obvious.” The Donkey Sanctuary publishes a Donkey Body Condition Score chart alongside its weight chart.

Most problems come from too much feed. The same UGA guide says donkeys usually need only 50 to 70 percent of the energy of a similar-sized horse and do best on high-fiber forage such as straw or coarse hay, with limited pasture and rarely any grain. Obesity, laminitis and metabolic problems follow from feeding a donkey like a horse. Our mini donkey hay guide covers forage choices, and the principles scale up to standards.

Lose weight slowly, never by starving. The Donkey Sanctuary advises that an overweight donkey should lose no more than 5 kg (about 11 pounds) a month, fed little and often on low-energy, high-fiber feed. It warns not to starve an overweight donkey, because that can trigger hyperlipaemia. In its hyperlipaemia guidance, the Sanctuary describes a disease in which a donkey that stops eating floods its blood with fat, which “carries a high risk of death even when recognised and treated promptly.” Its rule: a dull donkey is a veterinary emergency. Call your vet the same day if your donkey goes off its food.

Underweight is a vet question too. The Sanctuary lists dental problems, age, past neglect, feed quality, the time of year and even a lost companion among the causes of weight loss, and advises a vet check first, shelter, and gradual diet changes.

Keep them in pairs. That lost-companion point is not a footnote. Donkeys form strong bonds, and The Donkey Sanctuary’s welfare team says separated donkeys can respond to the stress by refusing to eat, which can lead to hyperlipaemia (pair bonding in donkeys). Weigh and score both donkeys, not just the one that worries you.

Track your donkey’s weight on Creatures

A monthly record is what The Donkey Sanctuary recommends, and it is the part most owners let slide. Creatures keeps it in one place for free.

Step 1: estimate. Measure as above and read the chart, or enter heart girth and body length in the donkey weight calculator for a quick figure. No account needed. The help article on estimating animal weight with the weight calculator explains the inputs.

Step 2: record it on the donkey’s profile. Add each donkey to Creatures, then add a Physical Measurement record. Choose Estimated weight for a chart or calculator result and Measured weight when the vet weighs the donkey on a scale. Creatures keeps the two apart so a trend never mixes a tape estimate with a scale weight. Record height and heart girth too, so you can recheck the chart later.

Step 3: watch the trend and set a goal. The Measurements view on the Records tab charts every reading and shows the change over the period. For a donkey that needs to slim down, set an “at most” goal with a target date that allows for The Donkey Sanctuary’s slow pace of loss, and add a progress photo with each reading. Track weight and growth walks through goals and progress photos.

Step 4: make it monthly. Track regularly turns the weigh-in into a recurring care plan step, so the next one appears on your list. Hoof trims, dental checks and vaccinations can live on the same profile, so a change in weight lines up with whatever caused it.

The calculator and record sheet open for any visitor; saving records needs a free account.

Frequently asked questions

How much does a donkey weigh?
Adult donkeys weigh about 100 to 500 kg (220 to 1,100 pounds) depending on size, according to The Donkey Sanctuary. Its own herd examples are 165 kg for a standard and 144 kg for a miniature; the BLM puts wild burros at about 500 pounds; and The Livestock Conservancy gives 900 to 1,200 pounds for Mammoth Jackstock.

How much does a standard donkey weigh?
Standards are 36 to 48 inches at the withers. The Donkey Sanctuary cites 165 kg (about 364 pounds) for a standard in its herd, and the BLM says wild burros average about 500 pounds at 44 inches.

How much does a mammoth donkey weigh?
The Livestock Conservancy says American Mammoth Jackstock weigh between 900 and 1,200 pounds, varying with height.

Can I use a horse weight tape on a donkey?
No. Donkeys carry their weight differently from horses, and the ASPCA’s donkey guidance says not to use a horse tape. Use The Donkey Sanctuary’s height and heart girth chart or a donkey formula.

How accurate is the donkey weight calculator?
It is a quick estimate from heart girth and body length using a general formula that has not been validated on donkeys, so we cannot give it a donkey accuracy figure. In our hypothetical worked example it came out below the Pearson and Ouassat donkey equation, but that example used illustrative numbers, not measured donkeys. Use it to track a trend, and use The Donkey Sanctuary chart or your veterinarian when you need a number to act on.

How often should I weigh my donkey?
The Donkey Sanctuary recommends recording weight and body condition monthly.

How much does a baby donkey weigh?
The Donkey Sanctuary chart is for donkeys over the age of two, and we did not find a published birth-weight standard across donkey sizes. Ask your veterinarian to weigh a foal when a number matters, and record its measurements as it grows.

Do this next on Creatures

Whether you keep a pair of standards, a pair of minis or a mammoth jack, here is where to go next.