🐾 Growth-curve model · 74 breed ranges · 100% free
Puppy Weight Calculator — Estimate Your Puppy's Adult Size
Enter your puppy's age and current weight to get an instant adult-weight range, a growth percentile chart, size-class classification, and gear-size matches. Refine the estimate with breed, sex, parent weights, birth date, and body condition — results update as you type.
Puppy Weight Calculator
Adult weight estimate, growth chart, and size match — updates as you type.
Your estimate appears here
Add age and current weight on the left — the estimate updates instantly as you type.
🔒 Everything runs in your browser — your puppy's numbers never leave your device.
One calculator, five answers
Every estimate runs through a growth-curve model, not a single division — then layers on the context owners actually ask for.
Instant formula + curve
The classic (weight ÷ weeks) × 52 number appears as you type, right next to the growth-curve estimate that corrects it for real puppy growth patterns.
Percentile chart
Your puppy is plotted against five size-class growth bands, with a dashed projection line to the predicted adult midpoint.
Birth date input
Skip the week-counting. Pick the birth date and the calculator derives the exact age in weeks and months for you.
Parent & BCS refinement
Blend in mother and father weights, neuter status, and a 1–9 body-condition score to tighten the range and correct for a puppy that is thin or heavy.
How to use this puppy calculator
Three steps from bathroom-scale number to a realistic adult-weight plan.
Start with basics
Enter age (weeks or months — or the birth date) and the most recent weight in kg or lb. Use a vet-scale weight when you can; kitchen-scale grams work for tiny breeds.
Add more detail
Pick the breed to lock in its adult range, set sex, note neuter status, drag the body-condition slider to match your puppy's ribs and waist, and open parent weights if you know them.
Track over time
Hit Save to store the estimate on your device, re-run every few weeks as your puppy grows, and compare the midpoint trend instead of obsessing over one number.
The formula behind the instant answer
The rule every breeder knows: adult weight ≈ (current weight ÷ age in weeks) × 52. It assumes perfectly linear growth, which real puppies do not follow — toy breeds hit adult weight around 8–9 months, while giant breeds keep gaining until 18–24 months. That is why the calculator shows the formula result and a growth-curve estimate side by side: use the formula for a quick sanity check, and the curve range for planning.
| Current weight | 5.2 kg (11.5 lb) |
| Age | 16 weeks |
| Instant formula | (5.2 ÷ 16) × 52 = 16.9 kg (37.3 lb) |
| Size class inferred | Small — 5.2 kg sits exactly on the 16-week small-breed band (3.2–7.2 kg) |
| Growth-curve estimate | ≈ 8.1–11.4 kg (17.9–25.1 lb) — tighter than the formula, because small breeds decelerate after 16 weeks while the formula keeps assuming linear growth |
And the “double the four-month weight” rule?
Another shortcut says an adult dog weighs roughly twice its 16-week weight. It only works for giants — smaller classes are already past the halfway mark at four months, so doubling overcounts the growth still ahead of them:
| Size class | Adult weight reached at 16 wks | Verdict for the ×2 rule |
|---|---|---|
| Toy | ≈ 56% | Overshoots by ~12% |
| Small | ≈ 53% | Overshoots by ~6% |
| Medium | ≈ 57% | Overshoots by ~14% |
| Large | ≈ 57% | Overshoots by ~14% |
| Giant | ≈ 50% | Lands on target — adult ≈ 2 × the 16-week weight |
The growth-curve estimate keeps the size class and your puppy's percentile in the math, which is why its range beats every fixed multiplier.
The five adult size classes
The calculator infers which band your puppy belongs to from age and weight, then locks onto that class's growth curve. Here is where each band lands at one year.
Toy
1.8–6 kg
4–13.2 lb
under 6 kg (13 lb)
≈ 15–28 cm at the shoulder
Fully grown ≈ 9 months
Small
5.5–14 kg
12.1–30.9 lb
6–14 kg (13–31 lb)
≈ 25–40 cm at the shoulder
Fully grown ≈ 10 months
Medium
12–25 kg
26.5–55.1 lb
14–25 kg (31–55 lb)
≈ 40–55 cm at the shoulder
Fully grown ≈ 12 months
Large
22–45 kg
48.5–99.2 lb
25–45 kg (55–99 lb)
≈ 55–68 cm at the shoulder
Fully grown ≈ 16 months
Giant
34–70 kg
75–154.3 lb
over 45 kg (99 lb)
≈ 68–90 cm at the shoulder
Fully grown ≈ 20 months
Puppy growth chart by age and size
Two views of the same growth bands the calculator runs on — what puppies of each size class typically weigh at each age, and how much of the adult frame is already in place.
Typical weight by age and size class
| Age | Toy | Small | Medium | Large | Giant |
|---|---|---|---|---|---|
| 8 weeks | 0.8–2 kg 1.8–4.4 lb | 1.8–4 kg 4–8.8 lb | 3.5–7.2 kg 7.7–15.9 lb | 6–12.5 kg 13.2–27.6 lb | 8.5–16 kg 18.7–35.3 lb |
| 12 weeks (3 mo) | 1–2.5 kg 2.2–5.5 lb | 2.5–5.5 kg 5.5–12.1 lb | 5.2–10.4 kg 11.5–22.9 lb | 9.2–18.5 kg 20.3–40.8 lb | 13.2–24.5 kg 29.1–54 lb |
| 16 weeks (4 mo) | 1.2–3.2 kg 2.6–7.1 lb | 3.2–7.2 kg 7.1–15.9 lb | 7–14 kg 15.4–30.9 lb | 12.8–25.5 kg 28.2–56.2 lb | 18.2–34 kg 40.1–75 lb |
| 20 weeks (5 mo) | 1.4–3.8 kg 3.1–8.4 lb | 3.8–8.8 kg 8.4–19.4 lb | 8.6–17.4 kg 19–38.4 lb | 15.8–31.5 kg 34.8–69.4 lb | 22.8–42.5 kg 50.3–93.7 lb |
| 24 weeks (6 mo) | 1.5–4.3 kg 3.3–9.5 lb | 4.4–10.2 kg 9.7–22.5 lb | 10.2–20.5 kg 22.5–45.2 lb | 18.5–36.5 kg 40.8–80.5 lb | 27–49 kg 59.5–108 lb |
| 52 weeks (1 yr) | 1.8–6 kg 4–13.2 lb | 5.5–14 kg 12.1–30.9 lb | 12–25 kg 26.5–55.1 lb | 22–45 kg 48.5–99.2 lb | 34–70 kg 75–154.3 lb |
Healthy puppies can sit anywhere inside their band — the columns are corridors, not targets. Toy and small breeds are nearly at their adult weight by the 52-week row; giant breeds keep filling out well past it.
Share of adult weight already reached
| Age | Toy | Small | Medium | Large | Giant |
|---|---|---|---|---|---|
| 8 weeks | 36% | 30% | 29% | 28% | 24% |
| 12 weeks (3 mo) | 45% | 41% | 42% | 41% | 36% |
| 16 weeks (4 mo) | 56% | 53% | 57% | 57% | 50% |
| 20 weeks (5 mo) | 67% | 65% | 70% | 71% | 63% |
| 24 weeks (6 mo) | 74% | 75% | 83% | 82% | 73% |
| 52 weeks (1 yr) | 100% | 100% | 100% | 100% | 100% |
Read as a share of the size class's one-year adult range. The gap between rows is the story: toy breeds sprint to 100% while giants are barely past half at six months.
Sanity-check any weigh-in without the calculator
Find your puppy's age row and size-class column in the percentage table, then divide: current weight ÷ that share ≈ implied adult midpoint. A 16-week small-breed puppy weighing 5.2 kg sits at ≈ 53% → 5.2 ÷ 0.53 ≈ 9.8 kg as an adult — right inside the calculator's 8.1–11.4 kg range for the same inputs.
Reading the growth percentile chart
After every estimate, the chart panel plots your puppy as an orange dot: age across the bottom, weight up the side. The colored bands are the healthy growth corridors for each of the five size classes, interpolated week by week.
The dashed line is the projection — it connects today's dot to the predicted adult midpoint at 52 weeks. A shallow slope means your puppy is already close to frame; a steep slope flags the heavy growth months still ahead, which is exactly when large and giant breeds need controlled feeding.
Watch the percentile, not the weight. A Lab at the 70th percentile of the large-breed band and a Beagle at the 70th percentile of the medium band are both growing exactly on trend. The same absolute kilograms would mean very different things.
Off-curve? What it usually means
- ▲ Above the band: common after a big meal or before a lengthwise growth spurt — recheck in 2 weeks before worrying.
- ▼ Below the band: check portion size, worming schedule, and stool quality; persistent under-band results deserve a vet visit.
- ● Crossing bands between checks: the size class inference has updated — look at the inputs list to confirm which curve is being used.
Getting a more accurate estimate
In validation work on puppy growth-curve models, roughly 8 in 10 purebred puppies land inside the predicted band, and the typical error shrinks from about ±15% at 3 months to ±7% by 9–12 months (Salt et al., 2017). Where your puppy sits on that spectrum:
| Puppy age | What the estimate can tell you |
|---|---|
| Under 8 weeks | Low — bands are at their widest; treat the midpoint as a compass heading only. |
| 8–12 weeks | Medium — the trend across two weigh-ins starts to mean more than any single result. |
| 12–24 weeks | The sweet spot — steady growth, meaningful percentiles, typical error around ±10%. |
| 6–12 months | Tight — the size class is locked in; the estimate mostly confirms and fine-tunes. |
✓Weigh at the same time of day
Pre-meal, post-potty, morning weigh-ins remove the ±5% noise of food and water in the gut — enough to shift the percentile band.
✓Use a recent weight
A 10-week-old puppy can gain 10% body weight in a single week. A 3-week-old weigh-in is worse than none for estimate quality.
✓Name the breed (or the parents)
Breed and parent weights each raise the confidence score. For mixed breeds, a rough parent weight beats a precise guess at the breed mix.
✓Score the body condition honestly
Run your hands over the ribs: feel without pressing = BCS 5. Need pressure = 6–7. Ribs and hip bones visible = 3–4. The slider adjusts the true target by ~10% per point.
✓Expect wobble at 12–20 weeks
Puppies grow in bursts — legs first, then chest depth and fill. Mid-growth estimates swing wider; the confidence badge will say so.
✓Re-run on a schedule
Every 2–4 weeks is enough. Save each estimate and compare midpoints: the trend matters more than any single result.
✓No dog scale? No problem
Tiny breeds: a kitchen scale plus a box reads to the gram. Bigger puppies: step on the bathroom scale holding your puppy, then subtract your own weight — within 100 g is plenty accurate for the band.
What shapes a puppy's adult size
The calculator quantifies the six factors that matter — some you can enter, some you can only manage.
Parents & genetics
The single biggest factor — puppies almost never outgrow their largest parent. When both parents are known, our model blends their average into 28% of the midpoint and tightens the range by about 12%.
Sex
Within the same breed and litter, males typically finish a few percent heavier. The model applies +3% for males and −3% for females once you set sex.
Neuter status & timing
Early neutering delays growth-plate closure, which can add a little height and weight — the model nudges +2%. After surgery, metabolism drops, so the same portions slowly build fat instead of frame.
Nutrition
Overfeeding never enlarges the genetic plan — it adds fat onto it and pushes growth faster than developing joints handle. Underfeeding, or a calcium-phosphorus imbalance, can genuinely stunt the frame.
Health basics
Roundworms, giardia and chronic loose stools steal calories before they become kilograms. A dewormed puppy with healthy stools tracks its curve far more reliably — check the schedule before worrying about the scale.
Exercise
Free play builds coordination and muscle safely. Forced distance work — jogging, long stair repeats — stresses joints that are still open, especially in large and giant breeds before 12–18 months.
Feeding and exercise for steady growth
The estimate is only half the job — here is the routine that keeps the growth curve smooth between weigh-ins.
Meals per day, by age
| Age | Meals/day |
|---|---|
| 8–12 weeks3–4 meals | Tiny stomachs, steady blood sugar — the schedule matters most for toy breeds at risk of hypoglycemia. |
| 3–6 months3 meals | Appetite surges with the sprint phase; keep portions measured, not free-fed. |
| 6–12 months2 meals | Growth decelerates; most puppies settle happily into the adult routine. |
| 12 months +2 meals | Switch to adult food around 9–12 mo for small breeds, 12–15 mo for large, 18–24 mo for giants — with your vet's sign-off. |
Treats: the 10% rule
Training treats, chews and table scraps should stay under 10% of daily calories. Puppy calorie budgets are small — treats that crowd out balanced food skew both nutrition and the next weigh-in.
The 5-minute rule
A classic guide for structured walks: about 5 minutes per month of age, up to twice a day — a 4-month-old gets roughly 20 minutes per outing. Beyond that, let free play at the puppy's own pace fill the quota.
Large & giant breeds: grow slow, grow right
Choose a large-breed puppy formula with controlled calcium and calories, skip free-feeding, and aim for a slow steady climb. A giant puppy that grows on-curve but slower ends up with healthier joints than one that surged ahead.
Feed to condition, not to the forecast
The projection is where your puppy is heading, not a quota to reach. If the scale drifts above the band, trim treats and re-measure in two weeks — never restrict a growing puppy's meals to hit a number. Body condition (BCS) is the daily guide; the calculator is the long-range map.
When owners usually recheck weight
Growth is not a straight line — each life stage changes what the number means and what to do about it.
6–12 weeks · Toddler
Rapid, fragile growth. Weigh weekly for small breeds at risk of hypoglycemia. Estimates here carry the widest ranges — treat the midpoint as a rough compass only.
3–6 months · Puppy sprint
The fastest growth window for most size classes. Legs lengthen before the chest fills, so the puppy looks lanky mid-stage. Re-run the estimate monthly and expect the percentile to stay steadier than the raw weight.
6–12 months · Fill-out phase
Height slows, muscle and chest depth catch up. Toy and small breeds are nearly done; large and giant breeds still have 30–40% of their adult weight to gain. Toy and small breeds can move to adult food around 9–12 months; larger classes stay on puppy formula longer.
12–24 months · Adult transition
Giant breeds keep filling out longest. Compare against the breed-standard adult range rather than the growth curve, and switch to adult food when the vet agrees the growth plates are closing — commonly 12–15 months for large breeds and 18–24 for giants.
The 60-second body condition check
The BCS slider in the calculator uses the standard 1–9 scale. You only need three touchpoints to place your puppy within one point.
BCS 3–4 · Thin
- • Ribs and spine visible or easily felt
- • Sharp waist tuck from the side
- • Hip bones prominent
Estimate shifts target up ~10–20% — review portions with your vet before increasing food.
BCS 5 · Ideal
- • Ribs felt without pressing
- • Waist visible from above
- • Belly tucks up from the side
No correction applied — the scale weight is the honest number.
BCS 6–9 · Heavy
- • Ribs need pressure to feel
- • Waist lost from above
- • Rounded, sagging belly
Estimate shifts target down ~10–30% — adjust meals before the growth plates close.
When a growth check deserves a vet visit
Most off-curve readings are noise — a big meal, a full bladder, a different scale. These patterns are different, and they are worth a professional's eyes.
Weight stalls or drops between checks
One flat weigh-in can be a scale fluke; two in a row across 2–4 weeks is a pattern. Growing puppies should never lose weight — a real drop gets same-week attention.
Climbing well above the band
Recheck portions and treat calories first. If the same steep curve persists toward the six-month mark, talk to your vet — WALTHAM cohort data links early-life over-conditioning with lifelong overweight risk.
Ribs sharply visible, stuck below the band
Check the deworming schedule and stool quality before adding food — persistent under-band growth plus a pot-bellied look is the classic parasite picture.
Limping, stiff stairs, reluctance to play
Growing joints complain for orthopedic reasons, not just growth spurts. Large and giant breeds deserve same-week attention for any limping — developmental orthopedic disease waits for no one.
Appetite, energy or stool changes riding along
Weight drift plus lethargy, vomiting or diarrhea is a vet conversation, not a calculator problem. The trend gives your vet a timeline — bring the saved results.
The six-month checkpoint
Make the six-month weigh-in a real one: same scale, same routine, result recorded. It is the single most informative check of the first year, and it sets the comparison point for everything after.
Breed quick starts
Pick a breed and the puppy weight calculator by breed locks onto its adult weight range instead of the inferred size-class band — or browse the full list from the calculator's searchable dropdown.
Labrador Retriever
Large25–36 kg (55.1–79.4 lb)
Estimate now →Golden Retriever
Large25–34 kg (55.1–75 lb)
Estimate now →German Shepherd
Large22–40 kg (48.5–88.2 lb)
Estimate now →French Bulldog
Small8–14 kg (17.6–30.9 lb)
Estimate now →Chihuahua
Toy1.5–3 kg (3.3–6.6 lb)
Estimate now →Dachshund
Small4–15 kg (8.8–33.1 lb)
Estimate now →Beagle
Medium9.1–13.6 kg (20.1–30 lb)
Estimate now →Rottweiler
Large36–61 kg (79.4–134.5 lb)
Estimate now →Great Dane
Giant50–79 kg (110.2–174.2 lb)
Estimate now →Yorkshire Terrier
Toy1.8–3.2 kg (4–7.1 lb)
Estimate now →Cavalier King Charles Spaniel
Small5.9–8.2 kg (13–18.1 lb)
Estimate now →Border Collie
Medium13.6–24.9 kg (30–54.9 lb)
Estimate now →Siberian Husky
Large15.9–27.2 kg (35.1–60 lb)
Estimate now →Shih Tzu
Toy4.1–7.3 kg (9–16.1 lb)
Estimate now →Cane Corso
Giant40.8–54.4 kg (89.9–119.9 lb)
Estimate now →How the model works — and where it can't help
The 5-step model
- Five size-class growth bands (WALTHAM-style charts) interpolated week by week.
- Your puppy's percentile position inside the age-matched band.
- Breed range and parent weights blend the midpoint and narrow the span.
- Sex, neuter status and body condition apply small, honest corrections.
- A confidence score reports how much the inputs actually support the answer.
What it can't do
- Guarantee a weight — it returns a range, not a verdict.
- Predict mixed breeds precisely — without parents, bands stay deliberately wide.
- Overcome noisy data — under 8 weeks, natural variance dominates the inputs.
- Handle giants beyond the chart — dogs heading past ~70 kg fall back to class curves.
- Diagnose thin or heavy — that is a body-condition and vet conversation.
- Replace veterinary advice, ever.
Your data stays local
- Every calculation runs in your browser — nothing is uploaded.
- Saved estimates live on your device only.
- No account, no puppy inputs in any server log, no sharing.
Planning tool only — not veterinary advice. Please don't feed more or less based on the results alone.
Sources & further reading
- Salt C., Morris P.J., German A.J., et al. (2017). Growth standard charts for monitoring bodyweight in dogs of different sizes. PLOS ONE. doi.org/10.1371/journal.pone.0182064
- Hawthorne A.J., Lowe D.M., Butterwick R.F. (2004). Body-weight changes during growth in puppies of different breeds. The Journal of Nutrition, 134(8). doi.org/10.1093/jn/134.8.2027S
- WALTHAM™ puppy growth charts — the size-class growth standard this model's bands follow.
- AKC breed standards — adult weight ranges behind the 74-breed registry.
- WSAVA Global Nutrition Guidelines — body condition scoring (BCS 1–9) used by the condition slider.
- Merck Veterinary Manual — puppy growth, development and nutrition background.
Puppy weight calculator FAQ
The questions owners ask before trusting a result.
A puppy weight calculator is a planning tool, not an exact adult weight guarantee. Our model blends five size-class growth curves with your inputs: age, current weight, breed range, parent weights, sex, and body condition. Accuracy improves sharply after 12 weeks, with a known breed, or with both parent weights — that is what the confidence badge reflects.
Ready for your puppy's next check-in?
Weigh, enter, compare. Two minutes today keeps the growth plan honest for the months ahead.
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