A healthy 4-week-old kitten often weighs 350–550 g (12–19 oz), and a steady weekly gain matters more than a single weigh-in.
If you’re asking because you’ve got a tiny kitten in front of you, you’re not alone. Four weeks is a weird in-between age: they still want milk, they’re starting to try food, and they can look “small” even when they’re doing fine.
This page gives you a clear range, what changes that number, and an easy way to track growth so you can spot trouble early without spiraling over one reading.
How Much Do 4 Week Old Kittens Weigh?
Most 4-week-old kittens land somewhere in the mid-hundreds of grams. A practical target range is 350–550 g. Some healthy kittens sit a bit outside that window, especially if they were born small, came from a large litter, or are a naturally petite type.
What you want to see is trend. A kitten that gains week to week and acts like a normal, busy four-weeker is usually on track, even if the number isn’t “textbook.”
| Age | Typical Weight Range | Typical Weekly Gain |
|---|---|---|
| Week 1 | 100–200 g (3.5–7 oz) | 70–100 g/week |
| Week 2 | 200–300 g (7–11 oz) | 70–100 g/week |
| Week 3 | 300–400 g (11–14 oz) | 70–100 g/week |
| Week 4 | 350–550 g (12–19 oz) | 70–120 g/week |
| Week 5 | 450–700 g (1.0–1.5 lb) | 80–140 g/week |
| Week 6 | 550–900 g (1.2–2.0 lb) | 90–160 g/week |
| Week 7 | 700–1,100 g (1.5–2.4 lb) | 90–170 g/week |
| Week 8 | 850–1,300 g (1.9–2.9 lb) | 90–180 g/week |
Those ranges come from common shelter and veterinary growth references, plus the widely used rule that kittens gain roughly 50–100 g per week during early growth. If your kitten is gaining in that ballpark, you’re usually in a good place.
4 Week Old Kitten Weight Range With Real-World Variables
Two kittens can be the same age and still look like different “sizes of kitten.” Here are the usual reasons, without the scary stuff.
Litter size and early competition
Big litters split milk eight ways. Some kittens get pushed off the best spot. If you’re caring for a litter, rotating who nurses first and doing quick daily weights can keep the smallest from falling behind.
Sex and adult type
At four weeks, sex differences aren’t dramatic, yet they can start to show. Large adult types may carry a bit more weight early. Petite adult types can stay lighter while still gaining nicely.
Health and hydration
A single weigh-in can swing if the kitten just ate, peed, or got mildly dehydrated from diarrhea. That’s why the same time-of-day routine is gold.
How To Weigh A 4-Week-Old Kitten So The Number Means Something
You don’t need fancy gear. You need consistency each single time.
- Use grams. A kitchen scale that reads in 1 g steps is ideal.
- Pick a routine. Same time each day, before a big meal if you can.
- Use a bowl or small box. Tare it to zero, then add the kitten.
- Write it down. A notebook works. A phone note works. The act of logging is what matters.
- Watch the line, not the dot. Two or three days of data tells you far more than a single number.
If you’re raising an orphan, many neonatal care guides suggest daily weights early on, then spacing out once growth is steady. Merck’s veterinary reference also notes the rapid early growth pattern and typical weekly gain for kittens.
Tip: if they squirm, wrap them in a small towel, place them in a tared bowl, and read the number once it settles. For litters, mark kittens with colored collars or a tiny dab of nail polish on one toenail so logs stay matched.
What Counts As “Normal” Growth At Four Weeks
At four weeks, normal often looks like this:
- Weight rises most weeks, often around 70–120 g across a week.
- Energy is up: more play, more wobble-run, more curiosity.
- Teeth are coming in, and they start tasting soft food.
Food changes can make weight seem jumpy. Many kittens start weaning around 3–5 weeks, which is the range noted in the AAHA kitten nutrition guidance. The switch from all-milk to “milk plus mush” can shift their belly fullness from day to day.
Feeding And Weaning Tips That Help Weight Stay On Track
A four-weeker is learning to eat, not living on solid food yet. You’re aiming for smooth progress, not a sudden flip.
Start with a soft, warm slurry
Mix canned kitten food with warm water or kitten milk replacer to make a loose porridge. Offer it in a shallow dish, then let the kitten lick your finger and find the plate. Expect a mess. That’s normal.
Keep milk in the plan
If the kitten is still nursing from mom, great. If you’re bottle feeding, don’t stop just because they licked food once. Their stomach is still small, and milk calories help keep weight moving up while they practice eating.
Feed small amounts more often
Four-week-old kittens do better with several mini-meals than one big serving. It keeps energy steady and reduces tummy upsets that can drag weight down.
Check the poop
Weaning poops can get soft for a day or two. Watery diarrhea, blood, or a kitten that stops gaining is a different story. If the scale trends down, call a vet.
When A 4-Week-Old Kitten’s Weight Is A Red Flag
Here’s when you should treat the scale like an alarm, not a trivia tool:
- No gain for 48 hours in a small kitten, or weight drops on two weigh-ins in a row.
- Cold body, weak suckle, or constant crying that doesn’t settle after feeding and warmth.
- Diarrhea plus low energy, sunken eyes, or dry gums.
- Big belly with poor growth, which can hint at parasites or other issues.
If you need an age-and-weight cross-check, the ASPCA kitten weight and age chart is a handy reference used by many rescuers and foster groups.
If you’re unsure about a “low” weight, pair it with behavior. A four-weeker that plays, grooms, and sleeps warm is often fine. A kitten that feels limp, refuses food, or breathes fast needs help, even if the scale looks fine. Bring your weight log to the vet.
Quick Checks That Pair Well With The Scale
Weight is one signal. Add these quick checks and you’ll catch more issues earlier.
Body feel
At four weeks, you should feel a little padding over ribs, not sharp bones. A kitten can be small and still have a healthy padded feel.
Warmth
Kittens can chill fast. If your kitten feels cool, warm them first, then feed. A cold kitten can’t digest well, and weight can stall.
Mouth and nursing
Watch for strong latching, steady swallowing, and a relaxed, sleepy finish after feeding. Weak suckle often shows up before weight drops hard.
Common Weight Problems At Four Weeks And What To Do
This table is built for real-life triage. It doesn’t replace a vet, yet it can help you decide your next step fast.
| What You See | Likely Cause | What To Do Next |
|---|---|---|
| Weight flat two days, kitten bright | Weaning shift, timing differences | Weigh same time daily, add one extra mini-meal |
| Weight down, kitten sleepy | Not enough intake, chilling | Warm first, then feed; call a vet if no quick rebound |
| Loose stool after new food | Food change too fast | Return to gentler slurry, slow the transition over a week |
| Bloated belly, thin body | Parasites common in kittens | Schedule deworming advice with a vet or shelter clinic |
| Milk dribbles from nose | Wrong bottle flow, aspiration risk | Stop feeding, keep head level, get vet guidance the same day |
| Gums dry, skin “tents” | Dehydration from diarrhea | Vet visit; kittens dehydrate fast and may need fluids |
| Tiny, steady gain | Runty start, large litter | Track weekly gain; celebrate the slope, not the starting point |
A Simple 7-Day Tracking Sheet You Can Copy
If you’re trying to answer how much do 4 week old kittens weigh? for a foster or rescue kitten, a one-week log beats any chart. Use this mini template and you’ll know if you’re winning.
- Day 1–7 weight (g): ______ / ______ / ______ / ______ / ______ / ______ / ______
- Weekly change (g): Day 7 minus Day 1 = ______
- Food note: nursing / bottle / slurry / wet food
- Stool note: normal / soft / watery
- Energy note: playful / quiet / sleepy
Small Tweaks That Often Fix Slow Gain
When a kitten is only a little behind, tiny changes can get the scale moving again.
Warm the food and the room
Cold food gets rejected. Cold kittens burn calories staying warm. Keep meals slightly warm to the touch, and keep their resting spot cozy.
Reduce stress at feeding time
Quiet, steady handling helps. With a litter, feed the smaller kittens first, then let the heavier ones follow.
Pick one good kitten food and stick with it
Switching brands back and forth is a fast way to end up with runny stool. Give any change a few days, and keep it gradual.
Takeaways To Keep On Your Fridge
- A healthy 4-week-old kitten often sits around 350–550 g, yet the week-to-week rise matters most for most kittens.
- Expect mess during weaning. Keep milk in the plan while they learn to eat.
- Weigh in grams on a schedule and log it. The trend answers the question.
- If weight drops, energy crashes, or diarrhea hits hard, get veterinary help fast.
When you’re stuck on the question how much do 4 week old kittens weigh?, remember this: charts give a ballpark, your own log gives the truth.