THE FIGHT LIFE
Most calculators multiply your resting burn by one vague "activity level" and call it a day — which is why they miss by hundreds of calories on anyone who actually trains. This one splits it: what your body costs at rest, what your day costs outside the gym, and what each session on the mats actually costs.
Your job, your errands, your steps — everything except training. Pick honestly. Training gets added separately below, so don't count it twice.
Add every session you train in a normal week. Each one is costed off its own intensity, your bodyweight, and how long it runs — not a blanket guess.
Total daily burn
—KCAL
Eat to hold
—KCAL / DAY
Resting burn. Mifflin-St Jeor (1990) — the equation that holds up best when you don't have a body-fat reading. It lands within 10% of a lab measurement for roughly 4 out of 5 people. No calipers, no scale, no guesswork about your lean mass.
Your day. A non-exercise multiplier applied to resting burn. These are deliberately lower than the multipliers you've seen elsewhere (1.2 / 1.375 / 1.55 / 1.725), because those bake training into the same number — which is how people end up double-counting their sessions and wondering why the scale won't move.
Training. Each session is priced with METs from the Compendium of Physical Activities: (MET − 1) × 0.0175 × kg × minutes. That −1 matters. A MET already includes the calories you'd have burned sitting still, and those are already in the two numbers above. Subtracting it is the difference between an estimate and a fantasy. Weekly total is spread across seven days, because your body doesn't run on a training-day-only budget.
Afterburn. Real, and smaller than the internet claims — usually under 10% of the session itself. It's inside the range rather than added on top as false precision.
The range. Every input here is an estimate, so the output is too. The band is the honest version. Use the middle as a starting point, eat there for two weeks, and let the scale and your training quality tell you where your real number is. That feedback beats any calculator, including this one.
Macros. Protein 2.2 g/kg cutting, 2.0 g/kg otherwise — high enough to hold muscle in a deficit. Fat 0.8–1.0 g/kg for hormones and joints. Carbs take the rest, because carbs are what pay for rounds. If you're carrying significant extra weight, run the macros off your goal weight instead.