How to estimate your horse's weight

Knowing roughly how much your horse weighs is useful for everything from feeding and forage planning to weight management.

The most accurate option is a weighbridge, but most owners do not have one sitting at the yard.

Fortunately, you can get a useful estimate using a weigh tape or a couple of simple body measurements.

If you already have your measurements, you can skip the maths and use our Horse Weight Estimator.

The quickest options

For day to day monitoring, a weigh tape or measurement formula is usually perfectly practical.

If an accurate weight is important, use a weighbridge where possible.

The most accurate method: a weighbridge

An equine weighbridge works just like a large set of scales.

The horse stands squarely on the platform and its actual bodyweight is displayed.

This is the best option where you need an accurate figure rather than an estimate.

You may be able to access one through:

• your veterinary practice
• an equine nutritionist
• a feed company
• a yard or equestrian centre
• a visiting horse health or weighbridge service

The British Horse Society also runs weighbridge visits through some of its horse health services.

Even if you only use a weighbridge occasionally, it can be useful for checking how close your normal at-home estimates are.

Using a horse weigh tape

A weigh tape is probably the easiest way to estimate your horse's weight at home.

Unlike a normal tape measure, a horse weigh tape has approximate bodyweight markings printed directly on it.

To use one:

1. Stand your horse square on a level surface.
2. Pass the tape around the horse's girth.
3. Position it just behind the elbows and around the base of the withers.
4. Pull the tape so it sits snugly against the horse without digging in.
5. Read the estimated weight from the tape.

Try to measure in the same place and in the same way each time.

Different weight tapes can give slightly different results, so if you are monitoring changes over time, use the same tape each time.

How accurate is a weigh tape?

A weigh tape gives you an estimate, not a guaranteed bodyweight.

The British Horse Society notes that weigh tapes may not give a completely accurate overall weight, but they are very useful for seeing whether a horse is gaining, losing or maintaining weight.

That makes them particularly useful for regular monitoring.

For example, whether a horse weighs exactly 487kg or 502kg may matter less for routine weight management than spotting that the same tape has moved from 480kg to 525kg over several weeks.

Estimating weight from body measurements

You can also estimate a horse's weight using its heart girth and body length.

Research has found a strong relationship between these measurements and bodyweight, and measurement formulas can be more accurate than simply guessing by eye.

You will need a normal flexible measuring tape.

Measure the heart girth

Stand your horse square on level ground.

Run the tape all the way around the horse where the girth would normally sit, passing just behind the elbows and around the body close to the base of the withers.

Record the measurement in centimetres.

Measure the body length

Measure from the point of the shoulder to the point of the buttock.

Keep the measurement consistent and take it along one side of the horse.

Record this in centimetres too.

Horse weight formula

A commonly used formula is:

Weight (kg) ≈ heart girth² × body length ÷ 11,900

Both measurements should be in centimetres.

For example, for a horse with:

• heart girth: 180cm
• body length: 160cm

The calculation is:

180 × 180 × 160 ÷ 11,900

Which gives an estimated weight of around:

436kg

You can avoid doing this manually by entering the measurements into our Horse Weight Estimator.

Why is it only an estimate?

Two horses with similar measurements can still have different actual weights.

Breed, build, muscle, fat distribution and overall body shape can all affect the result.

Research comparing estimation methods has found that measurement formulas can give useful results, but no formula can completely replace actually weighing the horse.

So treat a calculated weight as a good working estimate rather than pretending that 436kg means exactly 436kg.

Do not estimate weight by eye

Horses are surprisingly difficult to judge visually.

A thick winter coat, breed type and muscle development can all change how large or lean a horse appears.

Research comparing different methods has also found visual estimates to be less reliable than measurement-based methods.

If you want to know whether your horse is changing weight, take measurements rather than relying on photographs or memory.

Weight is not the same as body condition

This is an important distinction.

A weight measurement tells you how heavy the horse is.

It does not tell you whether that weight is healthy.

A 500kg cob and a 500kg Thoroughbred may have very different builds and body condition.

This is why weight monitoring should ideally be combined with body condition scoring, sometimes called fat scoring.

What is body condition scoring?

Body condition scoring involves looking at and physically feeling areas where horses tend to store fat.

The commonly used UK system scores the horse from 0 to 5.

You assess areas including:

• the neck and crest
• behind the shoulder
• the ribs
• the back and spine
• the pelvis and hindquarters
• around the tail head

The British Horse Society considers around 2.5 to 3 out of 5 a healthy fat covering for most horses, unless your vet advises otherwise.

Importantly, you need to use your hands.

A horse can look reasonably slim while still carrying significant fat around the crest, shoulders or hindquarters.

How often should you check your horse's weight?

For general monitoring, checking roughly every two weeks is a useful routine.

The BHS, Blue Cross and World Horse Welfare all recommend regular weigh taping alongside body condition scoring, with fortnightly checks commonly suggested.

You do not need to panic over tiny changes between individual readings.

Instead, keep a record and look at the trend over several weeks or months.

Keep your measurements consistent

Consistency is more important than chasing a perfectly precise number.

Try to:

• use the same weigh tape
• use the same measuring method
• measure in the same place
• have the horse standing square
• use the same person where possible
• record the result each time

If your technique changes, part of the apparent weight change may simply be measurement error.

Why knowing your horse's weight matters

Having a useful weight estimate can help with:

• calculating forage requirements
• planning feed quantities
• monitoring weight gain or loss
• checking horsebox or trailer payload
• discussing medication doses with your vet
• correctly using weight-based worming products
• tracking health and condition over time

It is particularly useful when feeding by bodyweight.

For example, a horse eating around 2% of bodyweight per day would have very different forage requirements at 350kg and 600kg.

See our How much hay does a horse need? guide for a practical explanation.

Estimating weight for wormers and medication

Avoid deliberately underestimating your horse's weight when using a product where the dose is based on bodyweight.

Follow the product instructions and veterinary advice.

If an accurate weight is particularly important, a weighbridge is preferable to relying on an estimate.

For prescribed medication, follow the dose given by your vet rather than calculating it yourself from this guide.

Monitoring weight through the year

A horse's weight can change considerably as:

• grass growth changes
• workload increases or decreases
• winter forage is introduced
• turnout changes
• rugs and winter coats make visual assessment harder
• age or health affects condition

Recording a weight estimate and body condition score regularly gives you a much clearer picture than noticing several months later that your horse suddenly looks different.

Once you know your horse's approximate weight, you can use our Winter Forage Planner to estimate how much forage you may need over the winter.

Useful StableMetric tools and guides

• Horse Weight Estimator - estimate bodyweight from simple measurements
• How much hay does a horse need? - calculate a starting daily forage allowance
• Winter Forage Planner - estimate your forage requirements over a longer period
• Hay Cost Calculator - turn your forage requirements into an estimated cost

The simple answer

If you have access to a weighbridge, use it for the most accurate bodyweight.

For everyday use, a weigh tape is quick and particularly useful for tracking changes over time.

For a more detailed estimate, measure your horse's heart girth and body length and use:

Heart girth² × body length ÷ 11,900 = estimated weight in kg

Or enter the measurements into our Horse Weight Estimator.

Whichever method you use, combine weight measurements with regular body condition scoring. The number on its own cannot tell you whether your horse is at a healthy weight.