Quick answer: The simplest way to track your cat's weight at home is to weigh yourself on a bathroom scale, weigh yourself again while holding your cat, and subtract the difference, doing this on the same scale at the same time of day every one to two weeks. Write each reading down so you can spot a trend rather than reacting to one odd number. Because weight can drift up or down slowly, a steady log is far more useful than a single weigh-in, and any change you can't explain is worth a conversation with your vet.
Why a cat's weight is worth tracking
Cats are experts at hiding how they feel. A cat that is gradually losing or gaining weight often looks and acts the same day to day, and because you see your cat constantly, slow changes are easy to miss. A fluffy coat makes it even harder to judge by eye.
As general guidance, vets often describe body weight as one of the easiest things an owner can monitor at home, because an unexplained change can be an early signal that something is going on, from a diet that no longer fits your cat's activity level to an issue that needs a checkup. The point of tracking is not to diagnose anything yourself. It's to notice a trend early enough to ask your vet about it instead of discovering it months later.
How to weigh a cat at home: three methods
Method 1: The bathroom scale trick
- Step on a digital bathroom scale by yourself and note your weight.
- Pick up your cat and step on again. Try to hold your cat still and keep your feet in the same position.
- Subtract the first number from the second. The difference is your cat's weight.
- Repeat two or three times and use the average, since bathroom scales can be a little inconsistent with small weights.
This method works for most cats and costs nothing. Its weakness is precision: many bathroom scales round to the nearest half pound or 0.1 kg, which can hide small changes in a lighter cat.
Method 2: A baby scale or kitchen scale
A digital baby scale (or a large kitchen scale for a small cat or kitten) gives readings in ounces or grams, which is much better for spotting small shifts. Put a towel or a shallow box on the scale, zero it, then place your cat on top. Treats help. If your cat won't sit still, weigh their carrier empty, then weigh it with the cat inside, and subtract.
Method 3: A litter box with a built-in weight sensor
Some smart litter boxes weigh your cat automatically every time they step in. The LitterLux Self-Cleaning Litter Box uses a weight sensor alongside its infrared sensor, and the Tuya app (connected over 2.4GHz WiFi) shows each cat's weight along with a visit history. The appeal is that you get a reading at every visit with zero effort, which makes trends easy to see over weeks and months. Think of it as a convenient trend tracker rather than a replacement for your vet's scale: if the app shows a change you didn't expect, confirm it on a dedicated scale and ask your vet.
How often should you weigh your cat?
For a healthy adult cat, weighing every one to two weeks is a reasonable general routine. Kittens grow quickly, so weekly weigh-ins are common while they're young. For senior cats, cats on a weight-management plan, or any cat your vet has asked you to keep an eye on, follow whatever schedule your vet recommends. Whatever cadence you choose, consistency matters more than frequency: same scale, same time of day, and ideally before a meal.
What's a normal weight for a cat?
There is no single "correct" number, because healthy weight depends on your cat's breed, frame and age. Rather than a target number, many vets use body condition scoring, which looks at how easily you can feel the ribs and whether your cat has a visible waist from above. The most useful comparison is your cat against their own history: what did they weigh at their last checkup, and which direction are they heading now? Your vet can tell you what a healthy range looks like for your specific cat.
Reading the trend: what to log alongside weight
Weight is more meaningful when you pair it with a few other everyday observations. A simple note on your phone is enough.
| What to log | Why it helps |
|---|---|
| Weight and date | Shows direction over time, not just one reading |
| Food type and amount | Explains many weight changes (a new food, extra treats, a second cat stealing meals) |
| Water intake | A noticeable change in drinking is worth mentioning to your vet |
| Litter box visits | More or fewer trips than usual, or straining, can go hand in hand with other changes |
| Activity and appetite | Context for whether a change seems to fit your cat's routine |
If you're not sure what a typical day at the litter box looks like, our guide on how many times a day a cat should use the litter box covers what's generally considered normal.
When a weight change means it's time to call the vet
As general guidance, a change you can't explain by a change in food or activity, a loss or gain that keeps going over several weigh-ins, or any weight change paired with other differences (appetite, thirst, litter box habits, energy, vomiting, or coat condition) is a reason to book a visit. Sudden changes deserve a sooner call. You don't need to wait until you're worried. This is doubly true for older cats, which we cover in our post on what senior cats really need from a litter box.
How a smart litter box fits into the picture
If you've ever meant to weigh your cat and forgotten for a month, automatic tracking solves the consistency problem. With LitterLux, every visit is logged with a weight reading, so you can open the app and see a trend line instead of trying to remember when you last checked. The box also records visit history and sends an alert when the sealed 9L waste drawer is full. For households with two cats, it supports cats from 1 to 8 kg (about 2.2 to 17.6 lb), and the weight data helps you tell your cats' visits apart. If you'd like to understand the sensors in more detail, see how a self-cleaning litter box works.
One honest caveat: a litter box scale measures your cat in motion, often mid-step, so individual readings can vary a little. That's fine for watching the trend, which is what you actually want. For an exact number, use a dedicated scale or the one at your vet's office.
Frequently asked questions
How do I weigh my cat without a pet scale?
Use the bathroom scale method: weigh yourself, weigh yourself holding your cat, and subtract. Repeat a few times and average the results. For better precision with a small cat or kitten, a digital kitchen or baby scale with a towel on top works well.
How much weight change in a cat is a concern?
Because cats are small, even a change that sounds minor can be a meaningful percentage of their body weight. Rather than fixing on a number, watch for a change that continues across several weigh-ins or that you can't explain. If you see that, ask your vet; they can tell you what matters for your cat's size and age.
Can a litter box really track my cat's weight?
Yes, some smart litter boxes include a weight sensor that records a reading each time your cat steps in. LitterLux shows these readings, along with a visit history, in the Tuya app. It's a convenient way to catch trends, though you should confirm any surprising change on a regular scale and talk to your vet.
Why is my cat losing weight but still eating?
There are many possible reasons, and some of them need a vet to sort out. If your cat is eating normally but the scale keeps going down, don't try to work it out at home; book a checkup and bring your weight log, which gives your vet a much clearer picture than a single reading.
The bottom line
You don't need special equipment to keep an eye on your cat's weight; a bathroom scale, a notes app and a regular routine will do. What matters is consistency and watching the direction of the trend, then looping in your vet whenever something changes that you can't explain. If you'd rather have that trend tracked automatically with every litter box visit, the LitterLux Self-Cleaning Litter Box logs your cat's weight and visit history in the app while it keeps the box clean for you.
