HomeBlog → Method
Method · 5 min read · Jan 2026

The math behind your calorie target.

Your daily energy goal isn't a guess. Here's the equation Hitt Fitness uses to get there — and why we treat its output as a starting point, not a verdict.

When you set up your profile, Hitt Fitness produces a daily calorie target almost instantly. Behind that number is a well-validated estimate of how much energy your body uses at rest.

Step 1: Resting metabolic rate

We use the Mifflin-St Jeor equation, which estimates resting metabolic rate (RMR) from your sex, age, height, and weight. Among the common prediction formulas, it's one of the most accurate for the general population — which is why it's our default and labeled ✓ Peer-reviewed

Step 2: Activity

RMR is only part of the story. We multiply it by an activity factor based on the level you choose — from sedentary to very active — to estimate your total daily energy expenditure (TDEE).

Step 3: Your goal

Every prediction equation has error bars. Two people with identical stats can differ by a few hundred calories a day. The formula gets you close; your own results dial it in.

Why we don't pretend it's exact

Activity multipliers are necessarily rough, and metabolism adapts as you lose or gain weight. That's why we treat the target as a hypothesis to test, not a number to obey. If the scale and your energy aren't tracking the way you expect after a couple of weeks, adjust — and the app makes that easy.

The takeaway

Good math gets you to a smart starting point fast. Honest tracking over a few weeks gets you to the number that's actually right for you.

← Back to the blog