Type in your puppy's weight today, the age in months, and roughly how big you think they'll get. We do the math and show a likely range. Honest math: puppies vary, so the answer does too.
Puppy weight todaylb or kg, weigh on a scale
lb
Agemonths (decimals OK — 2.5 = 10 weeks)
mo
Expected adult sizebest guess from breed or parents
Known purebred?single recognized breed = narrower band
Likely adult weight
26–35lb
Most likely around 30 lb. Medium dogs usually finish growing around 12 months.
At 4 mo
12.8–17.3 lb
At 7 mo
20.7–27.9 lb
At 9 mo
23.5–31.7 lb
Full grown
25.5–34.5 lb
Why this band
Known purebred — breed-specific growth curves narrow the band.
A range, not a single number — that's the honest version. Mixed-breed puppies surprise you both directions. The methodology page walks through the math. See methodology
Quick answers about PawsCalculator's calculators and how the numbers work — RER × MER, body condition scoring, food density, life-stage multipliers. Free, no signup. Not veterinary advice — for medical, feeding, or weight-loss decisions about your specific pet, talk to a licensed veterinarian.
Hi, I'm the PawsCalculator assistant. I answer questions about pet calorie, weight, age, and feeding math — and how the calculators on this site work. I'm not a veterinarian and I can't give personal veterinary advice. For weight-loss programs, prescription diets, or age-related illness, talk to a licensed veterinarian.
How the math works
Puppies grow on a curve, not a straight line. They grow fast in the first few months and slower as they get close to adult size. The trick is knowing where on the curve a puppy is at their current age — that tells you what fraction of the adult weight they've already reached.
The calculator divides your puppy's current weight by the expected percentage at that age. Example: a 4-month-old large breed puppy is at about 42% of adult weight. So a 30-pound 4-month-old large breed projects to about 71 pounds adult (30 ÷ 0.42 ≈ 71). Then it adds a confidence band on top — because no formula is exact.
When the prediction is most accurate
Best window: 3 to 6 months. Before 3 months, puppy weight varies too much from week to week — the prediction is noisy. After 6 months, the puppy is already 60-90% of the way to adult size, and you don't need a calculator to see where this is heading.
One opinion: the most useful single moment is the 4-month check-in. The math is at peak helpfulness, the puppy is the right size to be measurable on a regular bathroom scale, and you have time to plan a year of crate, food, and harness sizing before the dog is fully grown.
Common breed examples
Plug these into the calculator to see how the math plays out for different breed sizes.
Labrador Retriever, 4 months, 30 lb: size class large, projects to about 71 lb adult (band ~60-82 for known purebred). Slightly above breed average for males, dead center for the breed overall.
Golden Retriever, 4 months, 22 lb: size class large, projects to about 52 lb adult. On the lighter side — typical for females or smaller males.
German Shepherd, 4 months, 33 lb: size class large, projects to about 79 lb adult. Solid male GSD territory.
Standard Poodle, 4 months, 28 lb: size class large, projects to about 67 lb adult. Most males land between 60 and 75.
Mastiff (English), 4 months, 40 lb: size class giant, projects to about 114 lb adult — but the upper band stretches past 130. Giant breeds vary the most.
French Bulldog, 4 months, 12 lb: size class small (or toy depending on line), projects to about 20 lb adult. Pet Frenchies often run 22-28 — heavier than show standard.
Predicting mixed-breed puppy weight
Mixed-breed puppies vary more than purebreds. Set "Known purebred?" to No or Mixed in the calculator and the band widens to 25-30%. That widening is honest math — without breed-specific growth curves, the prediction is genuinely fuzzier.
One trick that helps a lot: if you know either parent's adult weight (sometimes the shelter knows the mom's size), drop it into the parent-weight field. That single data point is worth more than every other guess combined — it anchors the projection genetically and tightens the band by about 5 percentage points each side.
One more tip: paw size is a rough hint, not a rule. Puppies with proportionally big paws at 8 weeks tend toward the larger end of their size class, but it's noisy. Trust the math more than the paws.
Adult weight by breed
Here are the typical adult weight ranges for 20 popular breeds. Use them to pick the right size class in the calculator above.
Breed weights with body-shape notes
Pick a size tier to filter. Numbers are AKC standards; the drift column is the pattern vets see most often in that breed.
Breed
Male
Female
Common drift
French Bulldog
under 28 lb
under 28 lb
Brachycephalic plus low exercise tolerance — body shape 6–8 is common; extra fat compounds airway and heat issues.
Yorkshire Terrier
up to 7 lb
up to 7 lb
"Teacup" marketing pulls the breed past the 7-lb cap; pet Yorkies often run 8–12 lb. Coat hides drift.
Dachshund (standard)
16–32 lb
16–32 lb
IVDD (back-disc) risk scales with abdominal load — vets aggressively flag body shape 6 or higher in Dachshunds.
Pug
14–18 lb
14–18 lb
Top-three obesity-prone breed in clinical surveys — food-motivated, brachycephalic, sedentary by build.
Pomeranian
3–7 lb
3–7 lb
Show ring 4–6 lb; pet Poms drift to 8–12 lb. Dense coat hides body shape — palpate, don't eyeball.
Beagle
20–30 lb (15")
20–30 lb (15")
Used as the obesity research model — opportunistic over-eaters, regularly top obesity-prevalence rankings.
Australian Shepherd
50–65 lb
40–55 lb
Suburban Aussies under-exercised vs working-line genetics — gain abdominal fat fast.
Pembroke Welsh Corgi
up to 30 lb
up to 28 lb
Chondrodysplastic long back — every excess pound directly loads the spine.
Border Collie
30–55 lb
30–55 lb
Usually under-ideal, not over — outworks the bowl. Pattern reverses for retired or older BCs.
Boxer
65–80 lb
≈50–65 lb
Lean working build is breed-correct; cardiac-disease prevalence narrows the over-ideal margin.
Labrador Retriever
65–80 lb
55–70 lb
About 25% of Labs carry a POMC gene deletion that encodes constant hunger — adult Labs at body shape 7–9 is the clinical norm.
Golden Retriever
65–75 lb
55–65 lb
Treat-heavy training tradition; body shape drift typically shows up after age four when activity drops.
German Shepherd Dog
65–90 lb
50–70 lb
American show lines run heavier; over-ideal compounds existing hip and elbow dysplasia load.
Doberman Pinscher
75–100 lb
60–90 lb
Lean visible-musculature build is breed-correct — owners often misread it as "underweight" and over-feed.
Siberian Husky
45–60 lb
35–50 lb
Bred to run 100+ miles a day on minimal food — most pet huskies need far less kibble than generic calculators predict.
Standard Poodle
60–70 lb
40–50 lb
Coat hides body shape; over-ideal stresses the breed's orthopedic predispositions.
Rottweiler
95–135 lb
80–100 lb
Hip dysplasia and cruciate rupture risks are both weight-sensitive — vets target body shape 4–5 hard in this breed.
Bernese Mountain Dog
80–115 lb
70–95 lb
Median lifespan is short (7–8 years) — every excess pound shortens an already-short window.
Great Dane
140–175 lb
110–140 lb
Puppy growth-rate management matters more than adult weight; the calorie load required to over-feed an adult is enormous.
Mastiff (English)
160–230 lb
120–170 lb
Line between "breed-correct heavy" and "over-ideal" requires palpation, not eyeball — coat and bone hide a lot.
Weights from AKC breed standards. Drift notes from clinical-prevalence surveys (APOP, Banfield) and breed-specific veterinary literature — see Sources below.
See the growth curve view
This page focuses on the single number — what your puppy will weigh as an adult. If you want the month-by-month growth curve view (a chart of expected weight at each age, not just the final number), use the puppy growth calculator. Same engine, different default view.
Questions worth asking
How accurate is the puppy weight calculator?
For purebreds with known parent weights, the prediction is usually within 10-15% of actual adult weight. For mixed breeds without parent info, the band widens to 25-30% — the calculator shows a wider low-to-high range to be honest about that. The 4-month checkpoint is the sweet spot: before 3 months the math is mostly noise, and after 6 months the puppy is already most of the way grown.
What's the easiest way to predict my puppy's adult weight?
If you don't want to use the calculator, here's the size-class shortcut: at 4 months, a small-breed puppy is about 60% of adult weight, a medium-breed puppy is about 50% (the famous 'double the 4-month weight' rule), a large-breed puppy is about 42%, and a giant-breed puppy is only about 35%. Divide your puppy's current 4-month weight by the matching percentage to get an estimate.
Does my puppy's parents' weight matter for the prediction?
A lot. Parent weight is the strongest single predictor of adult size after current-weight-and-age. If you know one parent's adult weight, drop it into the parent-weight field. The math anchors the mid-line toward that weight and tightens the band by about 5 percentage points each side. Two known parent weights are even better — average them and use that.
What if I don't know the puppy's breed?
Pick the size class your puppy looks closest to based on current size + paw size + parent guesses. The calculator will use a wider band to account for the unknown — that's the right move. Mixed-breed puppies surprise people in both directions: the cute fluffy puppy at the shelter labeled 'small' can grow into a 70-pounder. Wider bands catch that.
Should I worry if my puppy weighs more than the prediction?
Not unless they're way over. Weight slightly above the high-end of the band is usually one of three things: a slightly bigger-than-average pup for the breed, an early growth spurt, or extra body shape (puppy fat). Weight way over — like 30% above the high end — is worth a vet conversation about feeding amounts, especially for large and giant breeds where pushing too-fast growth has real joint consequences.
Sources
Full source list with verbatim quotes lives at /methodology. Specific to this calculator:
WALTHAM Petcare Science Institute. Puppy growth charts and breed-specific growth-curve research — the canonical reference for size-class growth percentages. waltham.com/resources/puppy-growth-charts
American Kennel Club. Breed weight standards used for the breed table above. akc.org/dog-breeds
Wisdom Panel veterinary team. Puppy weight prediction methodology — the size-class multipliers used as the canonical formula benchmark. wisdompanel.com predicting puppy size