Kitten Weight Gain Tracker & Growth Curve
Turn weekly kitten weights into a growth flag
Kitten weight gain, growth flags and vet checks FAQ
How often should I weigh my kitten?
Most families weigh kittens once per week during routine growth, and more often (even daily) for very young, rescued or unwell kittens. This tracker is tuned for weekly checks: it compares this week’s weight with the number from exactly seven days ago and looks at the percentage change, not just the raw difference.
What does the green/amber/red growth flag mean?
The flag is a quick visual hint:
- GREEN — weekly gain sits inside the typical band for that age.
- AMBER — gain is slightly under or over the band; watch closely and consider a vet chat.
- RED — weight is flat, dropping or far below expected; call your vet as soon as you can.
It does not replace a full exam, but it helps you spot growth trends early.
Why does the tool ask for age as bands instead of exact weeks?
Growth expectations change a lot between a 1-week-old neonate and a 6-month-old junior cat. Age bands (0–4 weeks, 4–8 weeks, 8–16 weeks, 4–6 months, 6–12 months) let the calculator pick a sensible percentage range for weekly gain without forcing you to remember exact day counts. If your kitten sits between bands, choose whichever feels closest and ask your vet which band to use long-term.
Are the “healthy curve” numbers the same as a vet growth chart?
No. Veterinary growth charts are often based on large data sets and specific breeds. This tool simplifies things to a percentage gain window by age band. It is meant as a homeowner-friendly screening tool, not a replacement for breed-specific charts, radiographs or vet exams.
What if my kitten was underweight and is now catching up?
Some kittens need a period of catch-up growth after illness or rescue. In those cases, a higher-than-typical weekly gain might be perfectly appropriate but should be managed under direct veterinary guidance. If the flag stays amber or red for “fast gain”, check your vet plan rather than simply cutting food on your own.
Can I track multiple kittens or a whole litter?
Yes. Run the calculator for one kitten at a time, then use the copy summary button to paste each kitten’s results into a note, spreadsheet or printed chart. Litters often have runts and big littermates, so it is useful to track each kitten separately, even when they share a mum and a food bowl.
What else should I watch besides the number on the scale?
Weight is only one piece of the picture. Also keep an eye on body condition score, appetite, thirst, energy level, stool quality, coat, and behaviour. A kitten that is technically gaining weight but seems dull, has diarrhoea or struggles to breathe is still an emergency. In any doubt, you should contact a veterinarian urgently rather than relying on a calculator.
When should I call my vet about slow growth?
You should call your vet immediately if the flag shows red and your kitten is losing weight, not gaining for several days in a row, or acting unwell. Even in mild cases, a run of amber flags over several weeks is worth a phone call: your vet can review parasite control, diet, vaccination timing and any underlying issues that might be slowing growth.
How to use this kitten weight gain tracker & growth curve
This tool is built to turn simple weekly scale readings into a clear, vet-friendly story: how fast your kitten is gaining, how that compares with a typical curve for their age, and whether the number looks calm (green), borderline (amber) or concerning (red).
1. Choose US-first units and enter weekly weights
The tracker loads with pounds (lb) first for US users. If your notes or scale are in kilograms, switch the unit selector to kg; the calculator will then display weights in kg first with lb shown alongside. Enter your kitten’s current weight for this week and the weight from exactly seven days ago in the matching unit.
2. Pick the closest age band
Next, select the age band that best fits your kitten. Neonates and early-weaning kittens are expected to gain faster (a bigger percentage each week), while junior cats have much slower growth. The chosen band tells the tool which percentage gain window counts as “typical” for that stage.
3. Check weekly gain, g/day and the growth flag
When you tap Check growth curve, the result card shows:
- Current and last week’s weight in your chosen unit, plus the other unit in brackets.
- Weekly gain in the main unit and the difference in grams.
- Average grams per day over the last seven days.
- % gain versus last week, compared to the age-band’s “healthy” range.
- A GREEN, AMBER or RED flag with a short explanation.
This gives you a one-glance sense of whether your kitten is tracking close to expectations or drifting off the curve.
4. Use the copy summary button as your log
Hit Copy summary each week and paste the text into a notes app, email or spreadsheet. Over time you build a simple weekly growth chart with dates, weights and flags. If you ever need to see a vet urgently, you can hand over this history in seconds so they can look for patterns.
5. Let vet advice override any calculator
Growth bands in this tool are deliberately conservative and generic. Your own veterinarian may aim higher or lower depending on breed, body condition, past illness and the kind of diet you are using. Always let your vet’s plan override any online chart, especially for orphaned, premature or sick kittens.
Used this way, the tracker is a simple growth dashboard: it keeps weight numbers tidy, makes trends easy to spot, and gives you a clear way to communicate concerns, while your vet handles the medical decisions.
How the kitten growth curve math and flags work
The growth checker does not try to replace detailed veterinary growth charts. Instead it uses a small number of age-banded percentage ranges that line up with typical kitten growth patterns, then flags weeks that fall far below or above those ranges.
1. Converting everything to kilograms and grams
Whatever unit you choose (lb or kg), the calculator converts the weights to kilograms internally:
weight_kg = weight_lb × 0.4536 (if you started in pounds)
It then works with whole grams for weekly gain and grams-per-day numbers. At the end, it converts results back to your chosen unit, showing that number first and the other unit underneath in brackets.
2. Weekly gain and grams per day
Let W₁ be last week’s weight in kilograms and W₂ this week’s weight in kilograms. The tracker calculates:
Weekly gain (kg) = W₂ − W₁
Weekly gain (%) = (W₂ − W₁) ÷ W₁ × 100
Grams per day ≈ (W₂ − W₁) × 1000 ÷ 7
If W₂ ≤ W₁ (no gain or weight loss), the flag immediately leans towards red, because young kittens are normally gaining at least a little weight every week.
3. Age-band “healthy” percentage ranges
For each age band the tool stores a conservative weekly gain band as a percentage of last week’s weight:
- 0–4 weeks: roughly 10–25% per week (very rapid early growth).
- 4–8 weeks: roughly 7–20% per week.
- 8–16 weeks: roughly 5–15% per week.
- 4–6 months: roughly 3–8% per week.
- 6–12 months: roughly 1–4% per week.
Your kitten’s weekly percentage is compared to the chosen band, and the difference drives the flag and note in the right-hand column.
4. Turning the numbers into green, amber or red
The classification is intentionally simple:
- RED if weight is flat or dropping, or <60% of the band’s lower limit.
- AMBER if gain is between 60–100% of the lower limit, or far above the upper limit.
- GREEN if gain sits comfortably inside the band.
The text note under the flag explains whether the main concern is slow gain, stalled gain, weight loss or unusually fast gain, and suggests whether to simply recheck next week or to call a vet now.
Because every kitten is different, the maths stays deliberately transparent and adjustable. You can repeat the calculation by hand, keep your own chart, and always layer this simple curve with your veterinarian’s physical exams, parasite checks and diet advice.
References and further reading on kitten growth and weight tracking
Use this weight gain tracker alongside trusted veterinary nutrition and growth resources:
- WSAVA Global Nutrition Guidelines — framework for calories, body condition scoring and monitoring growth in dogs and cats.
- International Cat Care — Feeding your kitten — practical guidance on growth, weaning, meal frequency and monitoring weight at home.
- AAHA/AAFP Feline Life Stage Guidelines (PDF) — veterinary overview of kitten, junior and adult life stages, including growth and nutrition notes.
- Cornell Feline Health Center — Feeding your cat — background on calorie control, body condition scoring and long-term weight management.
Always give your veterinarian copies of any growth logs you keep and ask them to interpret trends, especially when kittens are very young, underweight, recovering from illness or on special diets.