Size guide

Henkelion size guide

Every size and weight we make in four tables: carriers by the pet inside, litter boxes by the cat and the corner, vests and ankle cuffs by the pound.

Pet carriers: measure your pet, not only the scale

Stand your pet on the floor and measure from the nose to the base of the tail, then from the floor to the top of the head. Compare both numbers with the pet size in the table, and the weight last. A long cat that weighs 12 lb can still need the Large. Only the Medium is designed for cabin travel, and every airline sets its own under-seat limit: our carrier guide sets the Medium against the limits Delta, American and Alaska publish.

Pet carrier sizes
Size	Outside	Pet fits within	Pet weight	Airplane cabin	Price
Medium	17 x 11 x 11 in	15 x 9 x 9 in	up to 15 lb	Yes, check your airline	from $23.48
Large	20 x 13 x 13 in	18 x 12 x 12 in	up to 25 lb	No	from $39.99

Litter boxes: the cat, then the corner

Measure your cat from the nose to the base of the tail. International Cat Care puts the ideal tray at one and a half times that length. Big cats take the M for that reason. Then measure the corner: the box plus room for the mat in front, and the height under any shelf above it.

Litter box sizes
Size	Outside	Volume	Mat	Scoop	Price
S	17 x 13.3 x 10.2 in	about 22 liters	11.8 x 11.8 in	9 x 4 in	from $29.99
M	20 x 14.2 x 11.8 in	about 26 liters	19.7 x 14.2 in	13 x 4.7 x 3.3 in	from $56.99

Weighted vests: one weight, chosen once

The weight of a Henkelion vest is sewn into its front and back pockets, so you pick it once. A Cleveland Clinic sports medicine specialist points to 5 to 10 percent of your body weight, and lighter is the way to start. Our weighted vest guide works the numbers for each of our six weights.

Weighted vest weights
Weight	Colors	Pack of two	Price
4 lb	Black	No	from $26.99
6 lb	Black	Yes	from $27.99
8 lb	Black, Gray, Blue	Yes	from $16.99
12 lb	Black, Gray, Blue, Pink, Purple	Yes	from $19.99
16 lb	Black	No	from $42.99
20 lb	Black	No	from $46.99

Ankle weights: per cuff, with bags you can remove

Our cuff weights are per cuff, so a 3 lb pair weighs 6 lb in your hands. Each pair holds ten removable bags, five a side, and fewer bags make a lighter cuff. Harvard Health keeps ankle weights for leg lifts and similar floor work rather than walks: our ankle weights guide shows how to use them.

Ankle weight options
Per cuff	Pair	Removable bags	Colors	Price
2 lb	4 lb	10 per pair, 5 per cuff	Black	from $18.89
3 lb	6 lb	10 per pair, 5 per cuff	Black, Gray, Blue, Pink	from $20.69
5 lb	10 lb	10 per pair, 5 per cuff	Gray, Blue, Pink, Purple	from $23.39
10 lb	20 lb	10 per pair, 5 per cuff	Black	from $44.99

Sizes come from the spec sheet of each product, and prices from our last catalog update. See our editorial policy for how we print figures.

This page is general product information, not medical or veterinary advice.

Sources

International Cat Care: Choosing a litter tray for your cat. States that the ideal tray length is one and a half times the cat's length from nose to base of tail, that rectangular trays give more room, that cats prefer about 3 cm of litter, that trays go somewhere quiet away from food, water, busy areas, cat flaps and full-length windows, that trays are scooped at least twice a day and fully washed every 2 to 4 weeks with clumping litter (weekly with non-clumping) using hot water and biological detergent, that cloudy disinfectants such as chloroxylenol are toxic to cats, that covered trays keep odor in but can leave some cats feeling vulnerable, and that cats with reduced mobility benefit from lower sides. Read October 31, 2026.
Cleveland Clinic: The Do's and Don'ts of Wearing Weighted Vests. A Cleveland Clinic sports medicine specialist says research favors a vest of 5 to 10% of body weight, that a vest should fit securely and breathe, that a vest alone won't build strength but helps with strength training, that walking and running are safe ways to start while biking and fast or balance-heavy activities call for care, and that people with previous injuries should consult a physician. Read October 31, 2026.
Harvard Health Publishing: Wearable weights: How they can help or hurt. A Spaulding physical therapist says ankle weights should not be worn while walking or in aerobics (they shift work to the quadriceps, cause a muscle imbalance and pull on the ankle joint, risking tendon or ligament injuries to knees, hips and back), that they help with leg and hip exercises such as leg lifts, that wrist weights suit curls and rows when you cannot grip a dumbbell but not cardio or walks, that a weighted vest should not exceed 10% of body weight and is not for people with back or neck problems, gives the side-lying leg lift repeated 10 times per side, and advises talking to a doctor first and starting with as little as a pound or two. Read October 31, 2026.
Delta Air Lines: Pet Travel Overview. States that under-seat space varies by aircraft and recommends a soft-sided kennel of at most 18 x 11 x 11 in as fitting most aircraft types, requires pets to move around without touching or sticking out from the sides, sets a minimum age of 8 weeks for domestic travel, ventilation on 3 sides for domestic flights, one personal or carry-on item besides the kennel, no bulkhead or exit row seats, removal of the pet from the kennel at the security checkpoint, and asks travelers to verify partner airline policies. Read October 31, 2026.
American Airlines: Pets (carry-on pet carrier guidelines and limits). Lists 18 x 11 x 11 in for soft-sided carriers on all flights and 19 x 13 x 9 in (mainline) and 16 x 12 x 8 in (American Eagle) for hard-sided kennels, says pets must fit comfortably inside the closed carrier and stay under the seat in front for the entire flight, allows one additional item, bars bulkhead and exit row seats, and requires pets within the U.S. to be at least 8 weeks old. Read October 31, 2026.
Alaska Airlines: Pets in Cabin. Lists 17 x 11 x 9.5 in as the soft-sided carrier size and bans hard-sided kennels in the cabin, requires pets to be at least eight weeks old, limits pets per flight with reservations before the day of travel, counts the carrier toward the carry-on allotment, bars exit and bulkhead rows, asks for absorbent lining, and says sedation is not advised because tranquilizer effects at altitude are unpredictable. Read October 31, 2026.

Questions

Henkelion sizes, answered

How do you measure your pet for a Henkelion carrier?

With your pet standing, measure from the nose to the base of the tail for the length and from the floor to the top of the head for the height. Compare both with the pet size of each carrier, not only the weight.

Which Henkelion vest weight is the right one for you?

Choose by the use. Light vests of 4 to 8 lb suit walks and first sessions, 12 lb is the most popular middle weight, and 16 and 20 lb suit short, hard sessions for people already used to a vest.

Which Henkelion litter box size fits your space?

The S box needs a corner of about 17 x 13.3 in, the M box about 20 x 14.2 in, plus room in front for the mat. Check the height under a shelf too: 10.2 in for S, 11.8 in for M.