A little help goes a long way. Find a tool/

Pets

Puppy Adult Weight Calculator

Free puppy weight calculator: enter your puppy's current age in weeks, weight and breed size class to project the likely adult weight, how much growth remains and the age of full size — from toy breeds to giants.

YOUR WORKSPACEFree to use. No sign-up.
—
Enter the puppy's details and press Project adult weight.

Estimate from published growth curves, not a guarantee — genetics, nutrition and litter sex all shift the outcome. Ask your vet to track growth at check-ups.

Deep dive guides

A LITTLE CONTEXT · 4 MIN READPuppy Growth Curves: Predicting Adult Weight Before It Happens
All 2 related guides

How puppy adult weight calculator works

Puppies grow along predictable curves once you account for breed size: a toy breed may be 30% of its adult weight at 8 weeks, while a giant breed is only about 16%. The calculator divides the puppy's current weight by the percentage of adult weight typically reached at its age for its size class, using a piecewise-linear growth table for toy, small, medium, large and giant dogs from 6 to 52 weeks.

The result is a projection with an honest spread: a likely range of about ±15% around the central estimate, because genetics (including which parent the puppy takes after), nutrition and sex all shift real outcomes. It also reports how much growth remains as a percentage and the approximate age of full size — around 9 months for toy breeds versus 21+ months for giants.

The projection is most accurate in mid-puppyhood (roughly 10 to 20 weeks) when growth is steadiest, and least reliable before 8 weeks or after puberty starts. Weigh the puppy on the same scale at the same time of day for consistent inputs, and re-run the calculation monthly — a projection that stays stable across months is far more trustworthy than any single point estimate.

Frequently asked questions

How big will my puppy get?
A common shortcut: divide current weight by the percentage of adult weight reached at that age for the breed size — a 6 kg, 12-week-old medium-breed puppy at roughly 37% of adult weight projects to about 16 kg. The calculator applies size-specific growth curves and gives a ±15% range.
When do dogs stop growing?
It depends on size: toy breeds mature around 8–10 months, small breeds 10–12 months, medium breeds about a year, large breeds 15–18 months, and giant breeds up to 2 years. Bones finish lengthening first, then muscle and chest depth continue filling out.
How accurate is a puppy weight calculator?
Treat the central estimate as a midpoint, not a promise — real dogs vary ±15% or more around curve predictions. Mixed-breed puppies with unknown parentage are the least predictable. The tool's range exists for exactly this reason.
Which breed size class is my puppy?
Estimate from the parents if known, or from expected adult ranges: toy up to about 6 kg (13 lb), small 6–12 kg (13–26 lb), medium 12–25 kg (26–55 lb), large 25–45 kg (55–100 lb), giant over 45 kg. Paw size relative to the body is a rough visual hint in young puppies.
Is this veterinary advice?
No — it is an estimate from published growth-curve patterns. Weight trajectory is genuinely important health information: puppies growing too fast or too slow should be discussed with a vet, who can also plot the puppy on a breed-specific growth standard.

Related tools

Pets

Dog Gestation Calculator

Mating date to due date: 63-day canine gestation with the 58–68 day window.

 Pets

Pet Food Portion Calculator

Turn your pet's weight and food calories into daily grams and per-meal amounts.

 Health

Ideal Weight Calculator

Ideal body weight calculator from four medical formulas.