Two measured meals a day, 30-60 g each for a 4-6 kg cat, beats a bowl you top up whenever it looks low. A 1 g kitchen scale settles the portion in about 5 seconds, and it is the only tool that catches a 20 percent drift before that drift turns into 500 g of extra body weight. Most refill routines fail for three boring reasons: no number, no clock, no storage rule.
Why a topped-up bowl fails
Dry food that sits in the bowl for 24 hours pulls humidity out of the air, loses aroma and oxidizes fat. Cats with a never-empty bowl take 12-20 small snacks a day instead of 2 meals, and daily intake creeps up 10-15 percent without anyone noticing. A 4 kg indoor cat needs roughly 235 kcal a day; an extra 30 kcal a day is 900 kcal a month, close to 100 g of body fat. Free feeding also hides illness: a cat that stops eating is invisible when the bowl is always half full, and 48 hours without food is a genuine liver risk in an overweight cat. Timed refills give you 2 data points a day, which is the first thing a vet asks for.
Portion size: 30-60 g, twice daily
Read the energy line on the label, usually 3.5-4.2 kcal per gram as fed, or 4.0-4.5 kcal per gram of dry matter. Divide daily energy by that figure, then split it into 2 meals 10-12 hours apart. Most 4-6 kg indoor cats land between 30 and 60 g per meal. A small 3 kg cat sits nearer 25-30 g; a 7 kg cat closer to 47-50 g. Recheck every 14 days and move the portion by 10 percent, never more. The bowl should be empty in 10-15 minutes. If it is licked clean in 90 seconds, the cat is bolting rather than starving, and the answer is a slower bowl, not a bigger one.
| Cat weight | Daily kcal at 1.2 x RER | Daily grams at 3.8 kcal/g | Grams per meal, 2 meals |
|---|---|---|---|
| 3.0 kg | 190 | 50 | 25 |
| 4.0 kg | 235 | 62 | 31 |
| 5.0 kg | 280 | 74 | 37 |
| 6.0 kg | 325 | 85 | 43 |
| 7.0 kg | 360 | 95 | 47 |
Three things to weigh, not scoop
Weigh the food on a 1 g scale, tared with the bowl sitting on it. Weigh the cat every 14 days on a baby scale, same time of day, and write the number down; 50 g resolution is enough to see a trend across 8 weeks. Weigh what comes back: if 10 g or more is left at 3 refills in a row, cut the portion by 10 percent. A marked scoop is a volume measure, and kibble bulk varies 15-25 percent between brands, so one cup of food A can hold 30 percent more calories than one cup of food B. Grams are the only unit that survives a brand change. If the label prints kcal per cup only, convert once: 8 oz of a 4.0 kcal/g food is about 113 g and roughly 450 kcal, and that single conversion saves you from redoing the math every time you open a new bag.
Four storage rules that protect the bag
One: keep the kibble in its original bag, folded shut, inside a hard container. The bag carries the batch code and the best-by date, and that code is the only recall trail you own. Two: store at 20-25 °C, out of sunlight and away from the dishwasher and the oven. Three: finish an opened bag within 6 weeks if it is 2 kg, 4 weeks if it is 7 kg or larger, and write the opening date on the bag in marker. Four: never refrigerate dry food. Moving a bag between 4 °C and 22 °C condenses water on the kibble surface, and surface moisture plus 14 percent fat is a mold and rancidity problem, not a freshness win. Wash the container in hot water and dry it fully every 4-6 weeks.
Timing, water and bowl position
Two meals 12 hours apart create a 12-hour overnight gap, which most adult cats handle without drama. Kittens under 6 months need 3-4 meals and should not go more than 6 hours without food. Put the bowl on a washable mat, 1-2 m away from the water bowl: many cats prefer to drink away from their food, and a cat on dry food needs roughly 40-60 ml of water per kg of body weight per day. If your cat takes under half of that, part wet food is an easier fix than coaxing. Read wet vs dry food before switching, keep daily kcal identical during the change, and swap 10 percent of the ration every 3 days.
When the routine needs a vet
Call the clinic if the cat loses more than 5 percent of body weight in 30 days, eats under 50 percent of the portion for 2 days, vomits 3 or more times in 24 hours, or stops drinking. Weight gain above 10 percent in 8 weeks on a measured portion usually means portion error first, treat calories second, medical cause third, and treats over 10 percent of daily kcal are the usual culprit. A cat that guards the bowl, eats in under 60 seconds and then vocalizes for 30 minutes needs a slow feeder bowl, not extra grams. Suspected poisoning from human food or a plant belongs in the toxic list, not in a bigger dinner.
Reset in five steps
- Weigh 2 days of food on a 1 g scale and write the total on the container lid.
- Set 2 alarms 12 hours apart, and lift the bowl after 20 minutes.
- Weigh the cat today, then every 14 days, on the same scale.
- Print the opening date on the bag; 2 kg bags get 6 weeks, 7 kg bags get 4.
- Book a check if weight moves more than 5 percent in 30 days in either direction.
Total time for the reset is about 20 minutes, plus 2 minutes a day at the bowl. The payoff shows up at week 8: a stable weight within 2 percent, an empty bowl in 10-15 minutes, and a portion number you can hand to a pet sitter without a paragraph of explanation.
Frequently asked
Can I just leave dry food out all day instead of two meals?
You can, but you lose the two things that matter most: a measured number and an early warning. Free-fed cats eat 12-20 times a day, intake drifts up 10-15 percent, and appetite loss stays invisible for days. Timed meals of 30-60 g twice daily give you a clean daily signal, and a 12-hour overnight gap is fine for most adult cats.
How long does an opened bag of dry food stay good?
Plan on 6 weeks for a 2 kg bag and 4 weeks for a 7 kg bag, counted from the opening date you write on the bag. Store it sealed at 20-25 °C, away from heat and sunlight, and never in the fridge, because condensation between 4 °C and room temperature makes kibble soft and mold-prone rather than fresher.
My cat seems hungry after 30 g. Should I add more?
Check speed first. If the bowl is empty in under 90 seconds and the cat then vocalizes, the problem is eating rate, not calories, so try a slow feeder and split the same grams into 3-4 smaller refills. If weight is still dropping more than 5 percent in 30 days, that is a vet conversation, not a portion increase.