How to Measure Your Dog for the Ruffwear Doubleback Full Body Harness

The Ruffwear Doubleback Full Body Harness is designed for dogs that need extra security, offering a second point of attachment and a full-body fit that prevents even the most determined escape artists from slipping out. But to get that escape-proof performance, the harness must fit correctly. Measuring your dog properly is the first and most important step.

In this guide, we'll walk you through how to take accurate measurements for the Doubleback harness, explain the key fit points, and share tips to ensure your dog is comfortable and secure. Whether you're preparing for a hike or just want peace of mind on walks, proper sizing makes all the difference.

What You'll Need

Before you start, gather a flexible measuring tape (like the kind used for sewing), a piece of string or ribbon if you don't have a tape, a pen and paper to record measurements, and your dog. It's best to measure your dog while they are standing on a flat, non-slip surface. If your dog is wiggly, have a helper hold them gently or offer treats to keep them still.

You'll also want to have the Ruffwear sizing chart handy. The Doubleback harness uses chest girth and neck girth to determine size. We'll show you exactly where to measure.

• Flexible measuring tape (or string and ruler)
• Pen and paper
• Treats for cooperation
• Your dog in a standing position

Step 1: Measure Chest Girth

Chest girth is the most critical measurement for the Doubleback harness. It determines how the harness wraps around the widest part of your dog's ribcage. To measure, place the tape around your dog's chest just behind the front legs. It should be snug but not tight—you should be able to slip two fingers between the tape and your dog's fur. Record this number in inches or centimeters.

If your dog has a deep chest or a barrel chest, make sure the tape is level all the way around. The Doubleback's full-body design relies on this measurement to keep the harness from shifting. A too-loose chest girth can allow your dog to back out, while a too-tight one can cause chafing.

Step 2: Measure Neck Girth

Neck girth is measured at the base of the neck, where a collar would normally sit. Wrap the tape around the widest part of your dog's neck, just above the shoulders. Again, it should be snug but comfortable. This measurement ensures the neck opening of the Doubleback is neither too loose (which could let the harness slide) nor too tight.

The Doubleback has a padded neck area for comfort, but if the neck girth is too large, the harness may rotate. If it's too small, your dog may feel restricted. Compare your measurement to the Ruffwear size chart to find the best match.

Step 3: Check Weight and Body Length

While chest and neck girth are the primary sizing factors, the Doubleback also considers your dog's weight and body length for a proper fit. Weigh your dog on a scale if possible, and measure body length from the base of the neck to the base of the tail. This helps confirm that the harness torso length will align with your dog's anatomy.

For example, a dog with a long back may need a larger size even if their chest girth is on the smaller side. The Doubleback's full-body coverage means the harness extends along the back, so length matters for comfort and freedom of movement.

• Use a bathroom scale for weight.
• Measure from the withers (shoulders) to the tail base for length.

Step 4: Compare with the Ruffwear Size Chart

Once you have all measurements, compare them to the official Ruffwear Doubleback size chart. The chart lists chest girth ranges for each size (e.g., Small, Medium, Large, etc.) and corresponding neck girth ranges. If your dog's measurements fall between two sizes, choose the larger size for comfort, but note that you may need to adjust the straps for a snug fit.

The Doubleback features multiple adjustment points—at the chest, neck, and belly—so you can fine-tune the fit. If your dog is at the top of a size range, consider the next size up to avoid restricted movement. For dogs with a deep chest but narrow neck, you may need to adjust the neck straps separately.

Step 5: Test the Fit

After selecting a size, put the harness on your dog and adjust all straps. The harness should be snug but not digging in. You should be able to fit two fingers under any strap. Check that the chest strap is centered on the sternum, not pressing into the throat. The belly strap should sit behind the ribcage, not on the ribs.

Have your dog walk, sit, and lie down to ensure the harness doesn't restrict movement. The Doubleback's full-body design should allow full range of motion. If you see any rubbing or hear your dog trying to scratch at the harness, recheck the fit and adjust as needed.

• Check for two-finger clearance under all straps.
• Observe your dog moving in the harness for a few minutes.
• Re-adjust after the first wear, as straps may settle.

Getting the right fit for your Ruffwear Doubleback Full Body Harness is essential for both comfort and security. By following these measuring steps and using the size chart, you can ensure your dog stays safe on every adventure. For more tips on choosing the perfect gear, explore our Front Range® Harness and Hi & LightTM Lightweight Dog Harness for other great options.