Sizing Guide

The Right Fit Starts Here

A well-fitted collar should be secure, comfortable, and suited to the way your dog moves through the day—at home, on the trail, in training, or in the field.

Each Red Maple K9 Gear product has its own size range and fit considerations. Measure your dog before ordering, then use the size chart shown on the individual product page.

If you are between sizes or have questions about fit, email us at hello@redmaplek9gear.com before ordering. We are glad to help.

What You'll Need

• A soft tailor's tape measure
• Or a piece of string and a ruler
• Your dog standing comfortably

Do not use a rigid metal tape measure. If you use string, mark where it overlaps, lay it flat, and measure it with a ruler.

How to Measure Your Dog

1. Measure where the collar will sit

Wrap the tape around the middle to lower part of your dog's neck, where the collar naturally rests—below the jaw and above the shoulders.

Keep the tape flat against the coat. Measure snugly, but do not pull tight or compress the fur.

2. Record the measurement

Write down the measurement in inches. Measure twice for accuracy.

For long-coated dogs, gently part or compress the coat enough to get a consistent measurement close to the neck. Do not measure only the outermost layer of fur.

3. Choose the right range

Compare your dog's neck measurement to the size range listed on the product page.

Choose the size that places your dog's measurement comfortably within the range—not at the very end whenever possible. If your dog falls at the top of a range, has a broad head, has a thick coat, or is still growing, contact us before ordering.

Check the Fit

Once the collar is on your dog:

• You should be able to slide two fingers comfortably between the collar and your dog's neck.
• The collar should not restrict breathing, swallowing, or normal movement.
• The collar should not be loose enough to slip over your dog's head.
• Check the fit regularly, especially for growing dogs, dogs whose coat changes seasonally, or dogs whose weight changes.

The two-finger check is a widely used starting point for collar fit; the appropriate amount of space can vary by dog size, coat, collar style, and intended use.

Collar Styles

Flat and adjustable collars

TrailSide Collar · Tandem Collar · Duke Collar

Measure your dog's neck where the collar will sit. Choose the size range that contains your dog's measurement and allows room for normal adjustment.

For these styles, a properly fitted collar should allow two fingers beneath the strap while remaining secure enough that it cannot slip over your dog's head.

Martingale and limited-slip collars

TrailSide Martingale Collar · BirdLine Limited-Slip Collar

Measure two places:

1. Neck: Around the middle of the neck where the collar will rest.
2. Head: Around the widest part of the head, usually over the ears and around the jawline.

Use the larger measurement when choosing a size, and refer to the product-specific size chart. A martingale or limited-slip collar must be able to pass over the head, then adjust correctly at the neck.

When fitted, the control loop should tighten under leash pressure without the hardware or adjustment points fully bottoming out. It should release again when tension is removed. A martingale that closes completely or remains tight can be too small or adjusted incorrectly.

Safety note: Martingale and limited-slip collars should be used with supervision. Do not leave a dog unattended while wearing a martingale or limited-slip collar, as any collar can pose an entanglement risk.

Center-ring collars

BirdLine Center-Ring Collar

Measure your dog's neck at the point where the collar will sit. Select the size range that contains the measurement and allows a comfortable two-finger fit.

The center ring should sit naturally in the intended position when the collar is fitted. Check fit before field or training use and inspect the collar and hardware before each outing.

Leashes and long leads

Leashes and long leads are generally selected by purpose and handling preference, not dog neck measurement.

• 3-foot training lead: Close control for training, transitions, and situations where you want your dog near you.
• 6-foot leash: Everyday walking, trail use, and regular handling.
• 20-foot long lead: Training, recall practice, supervised exploration, and service/support applications where additional working distance is needed.

Always choose equipment appropriate for your dog's size, strength, behavior, and intended use. Inspect all gear before use. Do not use worn, damaged, altered, or improperly fitted equipment.

Our Current Collar Ranges

Use this table as a quick reference. Always confirm the selected product page before ordering, because style-specific fit and adjustment ranges vary.

Collection / style	Current size ranges
BirdLine Center-Ring Collar	Size 1: 14–18 in. · Size 2: 17–22 in. · Size 3: 21–26 in.
BirdLine Limited-Slip Collar	Size 1: 14–17 in. · Size 2: 16–19 in. · Size 3: 18–21 in. · Size 4: 20–23 in.
TrailSide Collar	Size 1: 14–18 in. · Size 2: 17–22 in. · Size 3: 21–26 in.
TrailSide Martingale Collar	Size 1: 14–17 in. · Size 2: 16–19 in. · Size 3: 18–21 in. · Size 4: 20–23 in.
Duke Collar	Size 1: 14–18 in. · Size 2: 17–22 in. · Size 3: 21–26 in.
Tandem Collar	Refer to the product page for the hardware- and width-specific size options.

The listed product ranges match the active Red Maple K9 Gear catalog: adjustable collar sizes commonly span 14–18, 17–22, and 21–26 inches; the martingale and limited-slip styles use overlapping 14–17 through 20–23 inch ranges.

Still Not Sure?

Every dog is built differently. If you are between sizes, have a dog with a broad head, a thick seasonal coat, or need help choosing between a standard collar and a martingale/limited-slip style, send us a note before you order.

Email: hello@redmaplek9gear.com

Please include:

• Your dog's neck measurement
• Head measurement, if considering a martingale or limited-slip collar
• Breed or approximate weight/size
• The product you are considering
• How you plan to use the gear

We will help you find the right starting point.