How to Measure Your Dog for a Tweed or Waterproof Collar

By Collared Creatures | Published: 2026-10-13

Category: How-to Guides

Get a reliable collar fit in minutes. Learn how to measure your dog's neck for tweed or waterproof collars, account for coat and width, and check the fit.

Quick answer

Measure your dog's neck at the middle of the neck, not at the base or behind the ears. Use a soft tape or a piece of string, keep it snug but not tight, and add about two fingers of space. For waterproof Biothane collars, choose a size that sits within the middle of the listed range so the material can flex without pinching. For tweed collars, allow a little extra room for the fabric's thickness and your dog's coat.

Why measurement is different for tweed vs waterproof collars

Tweed and waterproof Biothane collars behave differently on the neck. Tweed is a woven fabric with some thickness and minimal stretch, so the fit you measure is close to the fit you get. Biothane is a coated webbing: it is waterproof, wipe-clean, and does not absorb water or stretch over time, but it can feel firmer against the coat. That firmness means a Biothane collar needs to sit smoothly without being overtightened. If you are measuring a dog with a thick or curly coat, measure over the coat, not under it, because the collar will sit on top of the fur. For very small breeds, a soft tape can be hard to keep in place; use a piece of string and then lay it flat against a ruler.

What you need before you start

You do not need special equipment. A flexible measuring tape, a piece of string, a ruler, and a few treats are enough. Work when your dog is calm, ideally after a walk or meal. If your dog is wriggly, measure twice and take the average. For a dog with a very thick coat, you may want a second person to hold the treat while you measure.

Flexible tape measure or string plus a ruler
Treats to keep your dog still
A note of the measurement in centimeters or inches
The collar's size chart from the product page

How to measure step by step

Place the tape around the middle of the neck, roughly where a collar naturally rests. This is usually just behind the ears and before the shoulders. Pull it snug enough that it does not slide down, but you should still be able to fit two fingers flat between the tape and the neck. Write down that number. Then check the collar's size range: if your dog measures 15 inches, look for a collar that covers at least 13 to 17 inches so you have adjustment room. For a 38mm dog collar size, the wider strap distributes pressure better on larger necks, but it can overwhelm a small breed. If your dog is between sizes, size up for tweed and consider the middle of the range for waterproof Biothane.

Common mistakes to avoid

The biggest mistake is measuring too low on the neck, near the shoulders, which gives a larger number and a loose collar. Another is measuring over a thick coat and then ordering a size that only fits when the dog is clipped. Do not add extra length for growth unless you are buying for a puppy; a collar that is too loose can slip off. Finally, check the hardware: a metal clasp or buckle adds a small amount of length, so if your dog is at the very top of a size range, the next size up may fit better.

Step-by-step collar measuring process

Gather your tools: Use a flexible tape measure or a piece of string and a ruler. Have treats ready to keep your dog still. Checkpoint: if you use string, mark the length with your finger and measure it flat against a ruler.
Find the middle of the neck: Place the tape around the neck, just behind the ears and before the shoulders. This is where a collar naturally sits. Common mistake: measuring too low near the shoulders gives a loose fit.
Measure snugly: Pull the tape so it is snug but not tight. You should be able to slide two fingers under the tape. Checkpoint: if you cannot fit two fingers, it is too tight; if the tape slides down, it is too loose.
Write down the number: Record the measurement in inches or centimeters. Measure again to confirm. Checkpoint: if the two measurements differ by more than half an inch, measure a third time and use the average.
Compare with the size chart: Find the collar's size range. Your dog's measurement should fall within the middle of the range, not at the very end. Common mistake: choosing a size that only fits at the tightest hole; leave room for adjustment.
Account for coat and width: If your dog has a thick coat, measure over the fur. For a 38mm dog collar, make sure the width suits your dog's neck size. Small breeds may need a narrower collar. Checkpoint: a collar that is too wide can rub; a collar that is too narrow can dig in.
Check the fit on your dog: Once the collar arrives, put it on and check that you can fit two fingers between the collar and the neck. Watch your dog move, sit, and lie down. Next step: if the collar slips over the head or feels tight, exchange for a different size.

Product facts to keep in mind

Dark Brown & Beige Multicolour Waterproof Biothane Buckle Dog Collar: Dark Brown & Beige Multicolour Waterproof Biothane Buckle Dog Collar – Handmade in Yorkshire. It has a buckle fastening and is made from waterproof Biothane. Available options include Neck Size & Collar Width, and Hardware Colour. The dual-colour design hides dirt well, and the buckle is familiar if your dog is used to a traditional fastening. Because you can choose neck size and width, measure carefully and pick the width that suits your dog's build.
Mauve Waterproof Biothane Metal Clasp Dog Collar: Mauve Waterproof Biothane Metal Clasp Dog Collar features an Alumix metal clasp with a quick-release design. Available in Small (9-14"), Medium (11-17"), Large (12-20") and Extra Large (16-26"). Options include Neck Size, Collar Width, and Hardware Colour. The quick-release clasp is handy for daily use, but the size ranges are specific. If your dog measures near the top of a range, choose the next size up so the clasp does not sit under tension.