A harness is one of the most important pieces of gear you'll buy for your dog. Get it right and walks become safer, more comfortable, and easier to manage. Get it wrong even slightly and a poorly fitted harness can cause chafing, restrict movement, or give your dog an easy escape route the moment they spot a squirrel.
This dog harness guide covers everything: the types of harness available, how to measure your dog correctly, how to fit a dog harness step by step, and what to look for once it's on. Whether you're buying for the first time or replacing an old one that no longer fits, this guide will walk you through it.
Harness vs Collar Which Does Your Dog Actually Need?
Before diving into sizing, it's worth understanding why a harness is often the better choice.
A collar works fine for dogs who walk calmly on a lead. It's quick and easy to put on and a convenient place to attach an ID tag. But for dogs who pull, lunge, or have a sensitive neck including brachycephalic breeds like Bulldogs and Pugs a collar puts direct pressure on the throat and windpipe, which can cause discomfort or injury over time.
A harness distributes pressure across the chest and shoulders instead. This means no strain on the neck, better control for you, and a more comfortable experience for your dog. For puppies still learning to walk on a lead, a well-fitted harness is almost always the safer starting point.
Types of Dog Harness - What's the Difference?
Not all harnesses are built the same. The right type depends on your dog's size, temperament, and what you need the harness for.
Step-In Harnesses
Step-in harnesses are easy to put on your dog simply steps their front legs into the loops and you clip the buckle at the back. They're a great option for dogs who don't like things going over their head. The downside is they can be less secure if not fitted well, so sizing accuracy matters more with this style.
Overhead / Back-Clip Harnesses
These slip over the dog's head and clip at the back. They offer a secure fit with multiple adjustment points and suit dogs who are comfortable with gear going over their face. The back-clip design is ideal for calm to moderate walkers. Our TheAusiePaw Nylon Dog Harness and TheAusiePaw Premium Dog Harness are excellent examples of this style lightweight, adjustable, and built for everyday use.
Front-Clip / No-Pull Harnesses
A front clip harness has a leash attachment point on the chest rather than the back. When your dog pulls, the lead redirects them toward you rather than letting them power forward. This makes front-clip styles highly effective for training dogs that pull on the lead. Our TheAusiePaw Dog Chest Harness is designed with exactly this in mind giving you control without restricting your dog's natural movement.
Reflective Harnesses
For early morning or evening walks, visibility matters. Our TheAusiePaw Reflective Safety Dog Harness and TheAusiePaw Reflective Comfort Dog Harness feature reflective detailing that makes your dog visible in low-light conditions an easy safety upgrade, especially in Australian suburbs where footpaths aren't always well lit.
Hi-Vis No-Pull Harness
For active dogs or those walked in high-traffic areas, the TheAusiePaw Hi-Vis No-Pull Dog Safety Vest combines visibility with gentle pull correction a practical choice for dogs in training.
How to Measure a Dog for a Harness
Getting the measurements right before you buy is the single most important step. A harness that looks the right size on a product page can still be wrong if your dog's proportions are unusual for their breed. Always measure your individual dog never guess based on breed alone.
You'll need a soft tape measure and, ideally, someone to help keep your dog still.
Measurement 1 - Chest Girth (Most Important)
This is the key measurement for fitting any dog's harness. Measure the widest part of your dog's chest this is the girth measurement, taken just behind the front legs, going all the way around.
Keep the tape measure snug against the coat but not compressing it. Note this number down in centimetres. This is the part of your dog that most harnesses are sized around, and it's where most poor fits happen.
Measurement 2 - Neck Circumference
Measure the thickest part of your dog's neck, just above the shoulders. This matters for overhead-style harnesses that need to fit comfortably over the head and sit correctly around the neck without rubbing.
Measurement 3 - Back Length (for Some Styles)
For vest-style harnesses, measuring the length of your dog's back from the base of the neck to the base of the tail gives you a better sense of fit. A medium-sized dog might have a shorter or longer back than another dog of similar chest size.
Once you have your measurements, compare them to the sizing guide for the specific harness you're considering. Sizing varies between styles, so always check the individual product chart rather than assuming your dog is a "medium" across all harnesses.
How to Fit a Dog Harness - Step by Step
Measuring is the first part. Fitting the harness correctly is equally important. A harness that's the right size but adjusted incorrectly is still a poorly fitted harness.
Step 1 - Put It On Calmly
Introduce the harness before you try to put it on. Let your dog sniff it, reward them, and keep the experience positive from the start. For step-in styles, lay the harness flat on the ground, guide your dog's front legs through the openings, and clip at the back. For overhead styles, gently slip it over the head, position it on the chest, and clip any side or belly buckles.
Step 2 - Check the Position
Once the harness is on, check that it's sitting in the right place:
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The chest strap should sit flat across the chest, below the throat not pressing on the windpipe
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Straps should not be sitting over or directly behind the front legs where they could cause rubbing
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The back clip should sit centred on the dog's back, between the shoulder blades
Step 3 - Use the Two-Finger Rule
This is the standard check for any harness: slide two fingers under each strap. If you can do this comfortably and the strap doesn't sag away from the body, the fit is correct. A harness should fit snug firm enough that it won't slip or rotate, but not so tight that it's restricting movement or pressing into the skin.
If the straps are so tight you can't fit two fingers underneath, loosen them. If you can fit more than two fingers, tighten them a harness that's too loose can slip and even allow your dog to back out of it, which is a safety risk.
Step 4 - Work the Adjustment Points
Most quality harnesses have multiple adjustment points typically the chest strap, the back strap, and sometimes the belly strap. Work each one until the harness fits snug all the way around without any strap sitting loose or digging in. Re-check the two-finger rule at each point after adjusting.
Step 5 - Watch Your Dog Move
Have your dog walk around, sit, and shake off. A correctly fitted harness should stay in position without rotating to one side, without the straps sliding up toward the neck, and without restricting movement of the front legs or shoulders. If anything shifts significantly with normal movement, go back to the adjustment points.
Signs of a Poorly Fitted Harness
Knowing what a bad fit looks like helps you catch problems early. Watch for:
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Rubbing or red patches: under the leg, around the chest, or near the armpits a sign the harness is too tight or positioned incorrectly
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Rotating to one side: during walks usually means the back strap is uneven or the chest strap is too loose
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Restricting movement:Â if your dog is shortening their stride or moving stiffly, the harness may be sitting too far forward on the shoulders
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Slipping:Â if the harness rotates or your dog can pull their legs out, it's too loose and needs tightening
How Often Should You Re-Check the Fit?
A harness that fitted perfectly in winter can feel tighter in summer if your dog gains weight or if a thick winter coat has been clipped. Make re-checking your dog's harness fit a monthly habit particularly for puppies who are still growing, where the fit can change significantly from one week to the next.
Find the Right Harness for Your Dog
A well-fitted harness makes every walk easier for you and for your dog. Browse our full range of dog harnesses at The Aussie Paw Drobe, including reflective styles, no-pull options, nylon everyday harnesses, and chest harnesses for dogs in training. Each product includes a sizing guide to help you find the right fit for your dog at home before you buy.