Losing fat isn't a feeling.
It's a number.
How many calories to eat. How many weeks it takes. How much protein to keep your muscle. Works whether you're on a GLP-1 or doing it the long way.
Here's what she told the calculator.
In about two minutes, this is exactly what you'll fill in for yourself.
That's the whole input. No logging. No fasting schedule. Just who you are today and where you want to be.
The math of fat loss, in three numbers.
There's no secret — the industry just prefers you not to know. Once you see the math, every diet book makes sense, and most of them stop mattering.
9 calories in a gram of fat. 1,000 grams in a kilo. A kilo of fat is 9,000 calories you don't eat. Every calculation on this site flows from that.
At a steady 500 Cal deficit, one kilo of fat takes about 2.57 weeks. That's the real pace. The scale can move faster — but most of what moves faster isn't fat.
Your BMR, your maintenance, your macros. Different body, different number. The playground above has them already — set your own and they recompute live.
The scale moves faster than your fat does.
If you've dropped 5 kg in a week before, you know the feeling. Real — but not fat. Here's what actually comes off, and in what order.
The one you want gone. 9 Cal per gram. Can't be lost faster than the math allows — about 0.5–1 kg per week at a sane deficit.
Carbs are stored with 2 g of water per gram of carb. Drop carbs, drop the water with them. Comes off in days. Goes back on in a meal.
The one you don't want gone. Lost when protein is too low or deficit is too steep. Especially at risk on GLP-1s, where appetite makes hitting protein hard.
Excess water the body holds while processing junk food. Clean up the diet, inflammation drops. Not fat, but genuinely makes you look leaner.
This is why fast-loss diets look miraculous for a week, then stall. You flushed water and glycogen — cheap to lose, cheap to put back on. Fat is the expensive one at 9,000 Cal a kilo, and the only one that actually changes how you look. The calculator above is calibrated to the expensive one.
Four steps. Three minutes. Zero fluff.
Age, height, weight. Two taps pick your activity level. Fifteen seconds.
How many kilos off. By when. No vague "feel better" targets. A number, a date.
BMR. Maintenance. Diet calories. Macros. Refeed. Eight lines. Everything.
Track in any app. MyFitnessPal, Cronometer, napkin. The number does the rest.
$7. Once. Forever.
Your numbers change as your weight does. Lifetime access means you come back, recalculate, and carry on — no resubscribing, no upsells, no funnel. One price, done.