Kitten Calorie Targets by Age: 200 to 80 kcal/kg

Kittens do not eat by the gram, they eat by the calorie, and the target moves every 2-3 weeks. Three anchors cover most of the first year: 200-250 kcal per kg of body weight at 8 weeks, 130-160 kcal/kg at 16 weeks, and 80-100 kcal/kg at 6 months. Everything else is arithmetic on today's weight.

The Three Anchors, and Why They Fall

A kitten at birth weighs 90-110 g and runs on roughly 25 kcal/day. By 8 weeks it is 0.8-1.0 kg and needs 200-250 kcal/kg, which is 194-226 kcal/day for a 0.9 kg kitten. Growth then slows in absolute terms per kilo of body weight: 4-6% of body weight gained per day at 3 weeks, 2% at 8 weeks, 1% at 16 weeks, 0.5% at 6 months. Energy per kilo has to fall with it, or the kitten becomes a 5 kg 6-month-old with joint stress before its growth plates close.

RER: 70 x Weight in kg to the 0.75

Resting energy requirement is 70 x (weight in kg)^0.75 kcal/day. For 0.9 kg, 0.9^0.75 = 0.92, so RER = 65 kcal/day. Multiply by the age factor to get the daily target, then divide by the food's calorie density. The common mistake is using the adult maintenance figure of 1.2 x RER: for the same 8-week kitten that gives 78 kcal/day, about 40% of what it actually burns, and the kitten simply stops gaining.

Factor Chart by Age

Age	Weight	RER kcal/day	Factor x RER	kcal/day	kcal/kg
4 weeks	0.45 kg	38	3.2-3.6	122-137	270-305
8 weeks	0.9 kg	65	3.0-3.5	194-226	216-252
12 weeks	1.3 kg	85	2.6-3.0	222-256	170-197
16 weeks	1.8 kg	109	2.2-2.5	239-272	133-151
6 months	3.0 kg	160	1.6-1.9	255-303	85-101
12 months	4.0 kg	198	1.2-1.4	238-277	59-69

From Calories to Grams of Food

Wet kitten food carries 70-100 kcal per 100 g; dry carries 380-420 kcal per 100 g. The 0.9 kg kitten at 210 kcal/day needs 210 to 300 g of wet food, or 50-55 g of dry. At 5 meals a day that is 42-60 g of wet food per meal, or 10-11 g of dry. Weigh the portion on a 1 g kitchen scale: a typical 60 mL measuring scoop holds anywhere from 40 to 62 g of the same kibble depending on how it is filled, a 20-30% swing that quietly doubles as an appetite problem. Feeding amounts per age and body condition are laid out in how much to feed a kitten.

Weigh Weekly on a 5 g Scale

Use a kitchen scale that reads to 5 g, weigh at the same time each week before the first meal, and write the number down. Expected gain: 70-100 g per week from 2 to 8 weeks, 60-90 g/week from 8 to 16 weeks, 40-60 g/week from 4 to 6 months, 20-30 g/week from 6 to 12 months. A healthy 8-week kitten sits at 0.8-1.0 kg, 12 weeks at 1.3-1.6 kg, 16 weeks at 1.8-2.2 kg, 6 months at 2.7-3.6 kg. Birth weight is the other early checkpoint; targets by day are in kitten birth weight targets.

Reading a Flat Week Correctly

One week at plus 20 g is noise if the kitten is active, eating, and passing normal stool. Two consecutive weeks under 50 g between 8 and 16 weeks is a signal. Check in this order: the scale (battery, hard floor, same spot), the food (a formula change from 400 to 350 kcal/100 g cuts 12% of calories without changing the scoop), competition in a multi-cat home where the kitten eats last, and worms, which are common enough at 8 weeks that most vets deworm on schedule rather than on suspicion. A kitten that gains 100 g a week but looks thin is a different case from one that has stopped gaining. Flat weeks also cluster around events: a vaccine at 8 or 12 weeks can cost 30-50 g over 3-4 days, and a deworming dose can do the same. Note the event next to the weight so a normal dip does not read as a trend.

Check Body Condition, Not Just the Scale

Weighing catches change over 7 days; hands catch body shape today. Score on the 9-point scale: at 4-5/9 you feel the ribs under a thin fat layer, see a waist from above, and the belly tucks up. Kittens normally sit at 4-5/9; a score of 3/9 or lower at 12 weeks means the calorie target is under-shooting, and 7/9 at 6 months means it is over-shooting. Run your hands along the spine and ribs once a week, on the same day as the weighing, because a fluffy kitten can hide 200 g of fat behind coat.

Treats, Milk, and the 10 Percent Cap

Treats stay under 10% of daily calories, which is 21 kcal for the 0.9 kg kitten. A 14 g cream treat is 6-8 kcal, so 3 tubes is the ceiling, not the daily plan. Cow's milk at 60 kcal per 100 mL and 4.7% lactose causes loose stool in most kittens; kitten milk replacer at 65-70 kcal/100 mL is the substitute if a kitten still wants liquid. Free-feeding dry food works for some litters but makes the weekly number meaningless, because you cannot see what was eaten.

When the Numbers Say See a Vet

Book an appointment if any of these holds: no weight gain for 7 days, a loss of 10% or more of body weight, under 50 g per week for 2 weeks running, a body condition score below 3/9 or above 6/9 at 6 months, a round belly with diarrhea or a dull coat, or a kitten eating 30% above target and still losing weight. Vomiting more than 2 times in 24 hours, refusal to eat for 12 hours, or a kitten under 12 weeks that stops nursing or eating is an same-day visit, not a wait-and-see. Log weight weekly in the kitten weight tool so the vet sees a curve rather than a single number.

Five Steps for This Week

• Weigh the kitten tonight on a 5 g scale and write the number with the date.
• Pick the factor for its age, multiply RER, and get a kcal/day range.
• Divide by the food's kcal/100 g and convert to grams per meal across 4-5 meals.
• Cap treats at 10% of calories, about 21 kcal at 8 weeks.
• Re-weigh 7 days later and compare against 50-100 g of expected gain.

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