βοΈ Cat Weight Tracker
Weigh, log, watch the trend. Record each weigh-in with an optional body-condition score, see change since the last check and since day one, and print a tidy one-page log to hand your vet. No account, no uploads β the log lives in this browser, on this device.
Whose log is this?
With a birth date, the chart reads in age-weeks while they're young β handy alongside the Kitten Growth Predictor.
Ideally the target your vet gave you. This tracker records and shows progress β it doesn't set the goal for you.
Add a weigh-in
Same scale, same time of day, before a meal β that's how trends stay honest.
The 9-point BCS is a hands-on judgement β around 4β5 is the usual ideal zone, but your vet's feel of the ribs is the real measure. New to it? Start with our Ideal Weight & BCS Checker.
π Your data never leaves this device. It's stored only in this browser (localStorage) β nothing is uploaded, there's no account and no sync. Clearing site data will erase it, so export a backup now and then.
Current weight
No weigh-ins yet β add the first one on the left.
Progress to target
Trend
The dashed line is the target weight, when one is set.
Weigh-in log
| Date | Weight | BCS | Change | Note |
|---|
Nothing logged yet. The first entry is the baseline every future change is measured against.
CSV export combines all your cats in one sheet (date, weight, BCS, notes). Importing a CSV merges by cat name and skips duplicates; restoring a JSON backup replaces the current data β export first if in doubt. Changed the food or the cat's weight lately? Recheck portions in the Calorie Calculator β
Working toward a target with your vet? The Cat Weight-Loss Planner turns this log into a step-by-step calorie plan β and can import these weigh-ins, so you never type them twice.
Why keep a weight log?
It's the trend your vet actually asks for
"Weigh monthly and bring the log" is standard vet advice because a single weigh-in says little and a trend says a lot. This tracker keeps the dates, the numbers and the body-condition scores in one place β and prints them on a single page for the visit.
Weight and condition, together
Two cats can weigh the same and be in very different shape. Logging an optional BCS at every weigh-in β our difference from basic trackers β shows whether the kilos are muscle, fluff or something to discuss. It also imports the target from our BCS Checker and hands you off to the Calorie Calculator when portions need a rethink.
Private by design
No account, no server, nothing uploaded. Your cats' records sit in this browser only, and CSV/JSON exports are your backup and your way to move devices. Free trackers with this log-and-chart pattern are rare for cats; the spreadsheet versions sell for real money.
Every cat in the house
Separate profiles per cat, each with its own unit preference and target β and one combined CSV when you want the whole household in a spreadsheet. Kittens get an age-in-weeks view when you add a birth date.
Questions people ask
How often should I weigh my cat?
Monthly is a good rhythm for a healthy adult; weekly for kittens (they should be gaining steadily) and for any cat on a vet-directed weight plan. Same scale, same time of day, before a meal β consistency matters more than frequency, because you're reading a trend, not a single number.
How do I weigh a cat who hates the scale?
The hold-and-subtract method: weigh yourself holding the cat, then weigh just yourself, and subtract. A carrier on a bathroom scale works the same way (weigh the empty carrier too). Kittens fit a kitchen scale and a mixing bowl. However you do it, write the method in the note and keep it the same.
My cat has lost weight. What does the alert mean?
This tracker only records numbers β it can't say why a weight changed, and lots of causes look identical on a chart. The one benchmark built in: a loss of more than 10% from the highest logged weight is considered clinically significant (the VCA benchmark), so the tracker flags it as a prompt to book a vet visit rather than something to watch and wait on. Rapid loss, or any loss alongside appetite or behaviour changes, means sooner, not later.
Where does my data live? Can I move it to a new phone?
Only in this browser's local storage, on this device. Nothing is uploaded and there's no cross-device sync β that's the privacy trade-off. To move or back up, export the JSON backup (or CSV) and import it on the other device. And note the honest warning: clearing this site's browser data erases the log, so keep an export somewhere safe.
What is the BCS number I'm logging?
Body Condition Score β a 1β9 hands-on scale vets use (ribs you can feel but not see is the classic middle). Logging it next to the weight matters because weight alone can't tell condition. If you've never scored your cat, our Ideal Weight & BCS Checker walks through it, estimates an ideal weight from it, and can send that target straight here.
Does it work for more than one cat?
Yes β add a profile per cat, switch between them at the top, and the combined CSV export puts the whole household in one sheet with a column per weigh-in, BCS included.
Keep exploring
Ideal Weight & BCS Checker β score condition and set the target Β· Calorie & Feeding Calculator β portions for the current weight Β· Kitten Growth Predictor β the expected curve for youngsters Β· All KittyButts tools
This is a record-keeping tool: it logs the weights and scores you enter and does the arithmetic on them. It never diagnoses anything, and no chart here can say why a cat's weight changed β weight change has many possible causes, and working out which one applies is a veterinarian's job. A loss of more than 10% from the highest logged weight is treated as clinically significant (VCA), so if the tracker flags it, book a vet visit. All data is stored only in your browser on this device.