When does a Labrador stop growing?

How big do Labradors get?

Per the American Kennel Club breed standard, adult male Labradors weigh 65 to 80 pounds and stand 22.5 to 24.5 inches at the shoulder. Adult females weigh 55 to 70 pounds at 21.5 to 23.5 inches. Pet Labs — not bred to show standard — often run a bit heavier, especially if they are over-fed and under-walked. Plenty of family Labs land at 85-95 pounds, which is overweight, not big-boned.

One thing the breed standard does not split out: English versus American line. English (show-line) Labs are blockier — broader chest, thicker neck, blockier head, shorter muzzle. They feel heavier than they look. American (field-line) Labs are leaner and more athletic, with longer legs and a narrower frame. Same height ranges, but different builds. An 80-pound English Lab and a 70-pound American Lab can be the same height to the inch.

One opinion: the "average Lab is 70 pounds" line you see online is misleading. Males are usually 75-80, females 60-65. Look at the actual sex of your dog, not the breed average.

The slow-growth window for Labs

Labradors are a large breed by the feeding-label definition (adult weight 55+ pounds), and large-breed puppies need to grow slowly. The reason is the growth plates — soft strips of cartilage at the ends of the long bones that close late in big dogs. In a Lab, the plates are still actively building bone at 14-16 months, even after weight has plateaued at 12. Push the dog to adult size by 10 months with too many calories and too much calcium, and the bones grow faster than the joints can handle. Hip and elbow dysplasia risk goes up.

What this looks like in practice: feed a food labeled for "growth of large-size dogs (70 lb or more as an adult)" until 14-18 months. Skip calcium supplements — for a large-breed puppy, more calcium is worse, not better. The bag's feeding chart is a starting point; the body-condition check is the actual gauge. You should be able to feel ribs with light pressure, see a waist from above, and see a tuck at the belly from the side.

One opinion: "your puppy is so big for the age" from the family vet visit is a feeding question, not a brag. If your 8-month Lab is already 70 pounds, that is not impressive — that is on track to be a 90-pound dog with bad joints by 5.

The Lab hunger gene

This one is real, and it is specific to Labradors. A 2016 study published in Cell Metabolism by Raffan and colleagues found that roughly 1 in 4 Labrador Retrievers carry a deletion in a gene called POMC. The deletion changes how the brain registers fullness — dogs with the variant feel under-fed even after a normal meal, are more food-motivated, and are more likely to be overweight as adults. The variant is even more common in assistance Labs, because the same trait makes the dog easier to train with food rewards.

What that means for feeding: the begging is real. Your Lab is not being dramatic and you have not failed at training. The brain wiring tells the dog the meal did not happen. The cure is not feeding more — the cure is measuring the food in cups, ignoring the puppy-eyes negotiation, and using the body-condition check as the gauge. If ribs are feel-able and the waist is visible, the food amount is right, even if the dog says otherwise.

One opinion: if your Lab is always begging, it might not be bad training — it might be the gene. That changes the strategy. Hunger-gene Labs do well on slow-feeder bowls, snuffle mats, and food-puzzle dispensers, because the same fixed amount of food takes 15 minutes to eat instead of 90 seconds. The brain still says "more please," but the dog at least has a longer chewing experience.

Lab growth pattern: fast, then slow

Labrador growth is front-loaded. From 2 to 6 months, the puppy roughly quadruples in weight — going from a 16-pound fluff to a 50-pound lean adolescent. That is the fast phase. Paws look huge because the bones in the feet finish before the leg bones; the body has to catch up to them.

From 6 to 14 months, growth slows to a steady fill-out. Weight goes from about 50 to about 70 pounds, but the rate per week is much lower. Height is mostly there by 12 months. After 14 months, growth plateaus — the bones are done, and the dog only fills out in muscle and chest depth for another 6-12 months. A 14-month-old Lab and a 24-month-old Lab can weigh the same and have the same height; the older one just looks bulkier through the shoulders.

Common Lab owner concerns

Too-fast growth.If your Lab puppy is at the top of the weight band for the age (or above it), the diet is the first thing to look at. Cut back to the lower end of the bag's feeding range, switch to a large-breed-puppy food if you are not already on one, and re-check body condition every 2 weeks. A vet visit makes sense if growth is fast AND lameness, lethargy, or joint clicking show up.

Hip dysplasia in big Labs.Labradors are the second most-affected breed for hip dysplasia after Bulldogs (per OFA's database). Risk goes up with adult weight, with growth speed during puppyhood, and with hereditary factors. The actionable lever is keeping the dog at body-condition score 4-5 out of 9 (lean, not chunky) for life. Lean Labs live noticeably longer than overweight Labs — Purina's lifespan study showed roughly 2 extra years.

Male versus female. Male Labs end up about 10-15 pounds heavier than females and a half-inch taller. They also tend to keep growing a month or two longer — most males are done at 16, most females at 14. Body shape differences come in after that: males get more chest depth, females stay leaner.

Food allergies.Labradors are one of the breeds most often diagnosed with food allergies. Common triggers in dogs are chicken, beef, dairy, wheat, and egg — not the grain-versus- grain-free question that gets the most internet attention. If your Lab has chronic ear infections, paw-licking, or skin issues that don't respond to flea control, an elimination diet (single novel protein plus single carb for 8 weeks) is the actual diagnostic move. Vet-supervised, not self-prescribed.

When to switch a Lab to adult food

14 to 18 months. Not 12. The 1-year birthday rule works fine for medium breeds (Beagles, Cocker Spaniels, Border Collies), but Labs are large breed, and large-breed puppy food has a calcium and phosphorus profile that supports the still-active growth plates. Switching at 12 months shorts that nutrient need by 2-6 months at the worst possible window.

What "adult food" means for a Lab: an all-life-stages or adult-maintenance kibble in a large-breed formula, fed by measured cups twice a day. Drop puppy food gradually over 7-10 days — half puppy, half adult, then quarter, then off — to avoid the soft-stool side effect of an abrupt switch. Once on adult food, calorie target is 1,300-1,700 kcal/day for a healthy adult Lab depending on size, age, and activity. The dog calorie calculator gives the per-dog number.

Questions worth asking

Sources

Full source list with verbatim quotes lives at /methodology. Specific to this guide:

• American Kennel Club. Labrador Retriever Breed Standard. Adult height/weight ranges by sex (males 22.5-24.5 in, 65-80 lb; females 21.5-23.5 in, 55-70 lb). akc.org/dog-breeds/labrador-retriever
• Raffan E, et al. Cell Metabolism, 2016. POMC deletion in Labrador Retrievers — links a deletion in the POMC gene to increased food motivation, weight gain, and obesity risk. Roughly 23 percent of pet Labs and 76 percent of assistance Labs carry the variant. cell.com Raffan 2016 POMC Labrador
• American Animal Hospital Association. 2019 AAHA Canine Life Stage Guidelines. Puppy life-stage definitions and the puppy-to-adult food-transition timing for large-breed dogs. aaha.org canine-life-stage-guidelines
• WALTHAM Petcare Science Institute. Puppy growth charts and growth-curve research — the canonical reference for size-class growth percentages. waltham.com/resources/puppy-growth-charts
• National Research Council. Nutrient Requirements of Dogs and Cats, 2006. Calcium and phosphorus requirements during the growth-plate-active window — the basis for the slow-growth feeding guidance for large-breed puppies like Labs. nap.nationalacademies.org/catalog/10668

Pairs with this guide: the puppy growth calculator (predicts adult weight with a confidence band), the puppy weight calculator (week-by-week target weights), the size-class growth timeline (toy through giant), and the dog calorie calculator (daily kcal target once your Lab is on adult food).