TDEE BMR Macro Calculator API for Fitness App Onboarding

Fitness app onboarding is where users decide if your product "gets them." A TDEE BMR macro calculator API fitness app onboarding flow collects age, weight, height, activity, and goal, then returns daily calories plus protein, carbs, and fat targets before the first meal log.

Technical reference: TDEE macro calculator API. This guide focuses on onboarding UX and integration.

Onboarding Screen Flow

API Call at Step 5

curl "https://api.calorieapi.com/api/v1/public/calc/macros\
?age=28&gender=female&weight_kg=65&height_cm=165\
&activity=moderately_active&goal=lose"

Store daily_targets in your user profile table.

React Onboarding Example

async function completeOnboarding(profile) {
  const params = new URLSearchParams({
    age: profile.age,
    gender: profile.gender,
    weight_kg: profile.weightKg,
    height_cm: profile.heightCm,
    activity: profile.activity,
    goal: profile.goal,
  });
  const res = await fetch(`/api/onboarding/macros?${params}`);
  const targets = await res.json();
  await saveUserProfile({ ...profile, targets: targets.daily_targets });
}

Proxy through your backend even though the calc endpoint is public, so you can add analytics and rate limits.

Results UI Mapping

Conversion Tips

• Show targets before asking for email when possible
• Pre-fill activity with "moderately active" as default
• Let users adjust protein upward for gym apps (bodybuilding guide)

After Onboarding

Food logging uses search and portion scaling against these targets.

Try calc in docs | Register free