How to Measure a Dog for a Coat: A Simple Size Guide
A size small from one brand can be a medium from another. XS, S and M have no universal meaning, and dogs of the same breed can still differ. One may be long in the body, another deep in the chest, a third thick through the neck.
The reliable approach is to measure your dog, then compare those figures with the size chart for the exact coat you are considering. This guide explains how to measure a dog for a coat, how to read a size chart and how to check the fit.
What you will need
A flexible tape measure, the soft kind used for sewing
A few small treats
A pen and paper, or a note on your phone
A second person, if you can: one to steady and reward your dog, the other to measure
No flexible tape? Use a piece of string or a shoelace. Mark where the measurement ends, then lay the string flat against a ruler or rigid tape measure and read off the centimetres.
Get your dog into position
Your dog should stand on all four paws, head up and relaxed, with weight spread evenly. Do not measure a dog who is sitting or lying down, because the body bunches up and the numbers will be misleading.
Reward calm standing with a treat before you begin. If your dog is wriggly, take a short break and try again.
The three measurements you need
PDSA's vet advice also covers length, chest and neck. Brands can start and end these measurements in slightly different places, so if a product page gives its own instructions, follow those.
How to measure the back length
Find the base of the neck, where the neck meets the shoulders. This is usually where a coat begins. Run the tape along the spine to the base of the tail and stop there.
Common mistakes:
Starting at the head or at the front edge of the collar
Measuring to the tip of the tail
Letting the tape sag into the dip behind the shoulders instead of following the spine
Adding extra centimetres yourself, rather than recording the exact figure
PDSA notes that longer breeds, such as Whippets and Lurchers, may need coats designed for their proportions.
How to measure the chest girth
To measure your dog's chest for a coat, take the full circumference of the widest part of the ribcage, which is usually just behind the front legs. Wrap the tape right round the body, under the chest and back over the spine.
The tape should:
Stay level all the way round
Rest against the fur without squeezing the chest
Leave your dog able to breathe normally
Common mistakes:
Pulling the tape tight
Measuring straight across the chest instead of all the way round
Letting the tape slip forward over the shoulders or back towards the waist
Measuring over a harness
A coat needs to close around the body without pressing on the chest or getting in the way of the shoulders and front legs. How much each measurement matters depends on the design and instructions of each product.
How to measure the neck
Measure around the base of the neck, where the opening of the coat will sit. This point can be lower than the thin collar your dog wears every day, so do not simply copy the collar's position. Let the tape rest against the fur without pulling it tight.
Common mistakes:
Measuring the collar instead of the dog
Measuring high up near the head
Pressing thick fur flat, or pulling the tape tight
Measure twice before choosing
Take each measurement twice. If the results do not match, reposition your dog and measure again.
Write the figures down in centimetres, labelled back, chest and neck. Many UK size charts use centimetres, though some use inches. PDSA suggests keeping both, which helps if you shop across several brands.
How to read a dog coat size chart
Size labels differ between brands, and weight or breed alone is only a rough guide. A 6 kg dog can be long and slim or short and stocky, and the same coat will not suit both.
When using a dog coat size guide from a UK retailer, always:
Use the chart for the exact coat you are buying, not a general guide.
Compare all three of your dog's measurements, not just one.
Check how that product describes each measurement.
Dog raincoat sizing works the same way. A chart is only useful for the coat it belongs to.
What if your dog is between sizes?
It happens often. Your dog might fit one size for chest and the next for back length.
Follow the instructions for that specific product first. Then:
Check which measurement falls outside the size
Consider whether the next size up would be too long or loose for your dog's body
Look for adjustable areas on the coat, if it has any
For the Wrenford raincoat, the current instruction is to choose the larger option when your dog falls between two listed sizes. Please check the current product page before buying, in case the chart or guidance has been updated.
The chart below applies only to this raincoat. It is not a universal chart, and it uses three measurements: back, chest and neck.
Size | Back | Chest | Neck |
XS | 20 cm | 32 cm | 23 cm |
S | 25 cm | 37 cm | 26 cm |
M | 30 cm | 42 cm | 29 cm |
L | 35 cm | 47 cm | 32 cm |
XL | 40 cm | 52 cm | 35 cm |
How should a dog coat fit?
The RSPCA advises that a coat should be snug but not restrict movement, and that your dog should still be able to behave normally, including going to the toilet easily. Once the coat is on, check that your dog can:
Walk and turn normally
Sit and lie down comfortably
Move the shoulders and front legs freely
Breathe without pressure around the chest or neck
Urinate and defecate without the coat getting in the way
Watch your dog for a few minutes indoors before heading out. PDSA says biting or scratching at the coat, or rubbing against the floor or furniture, are signs that it does not fit properly. If you notice any of these, take the coat off and recheck your measurements. If your dog seems unwell or in pain, speak to your vet.
Raincoat or winter coat?
They do different jobs. A raincoat is intended to reduce exposure to wet weather, while a winter coat prioritises warmth and may include padding or fleece.
Not every dog needs either. PDSA says dogs with fine or thin fur, and those that are very young, old, underweight or unwell, feel the cold more. It also notes that small breeds can feel the cold quickly, while a fit, healthy dog with thick fur is usually fine outside without a coat while active. If you are unsure, ask your vet.
If your dog does get wet, the RSPCA recommends drying them fully afterwards, as damp fur can leave them feeling cold and can lead to skin irritation.
Quick checklist
Stand your dog on all four paws
Measure the back length, from the base of the neck to the base of the tail
Measure the chest girth, round the widest part of the ribcage
Measure around the base of the neck, where the coat opening will sit
Measure twice and record in centimetres
Compare your figures with the chart for the exact coat
If between sizes, follow the product guidance
Check that your dog can walk, sit, lie down, breathe and toilet comfortably
Watch for biting, scratching or rubbing
Choosing with confidence
Once your three measurements are written down, choosing a coat becomes much easier, whichever brand you buy from. If you are looking for a raincoat for a small dog, the Full-Coverage Raincoat for Small Dogs is designed with extended coverage across the body and legs to help reduce the rain, splashes and mud that reach the dog's coat during everyday walks.
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