How Diet2Fit calculates your daily calories
Updated 2026-07-06
Your daily calorie target is not a magic number — it comes from a simple, well-established chain of maths: your body's baseline burn, adjusted for how much you move, adjusted again for your goal. Understanding this chain helps you trust the number, and tells you exactly when it needs updating.
Step 1: BMR — what your body burns at rest
BMR (Basal Metabolic Rate) is the energy your body would use if you did nothing all day — just breathing, circulation, keeping organs running. It is estimated from your age, sex, height, and weight. A taller, heavier, younger person has a higher BMR; that is why two people eating the same thali can have very different results.
Curious about your own number? The BMR/TDEE calculator in the app lets you play with the inputs and see how the estimate changes.
Step 2: TDEE — adding your daily activity
BMR alone is not what you burn in a real day. TDEE (Total Daily Energy Expenditure) multiplies your BMR by an activity factor based on the activity level you chose in your profile — from mostly sedentary through very active. Someone on their feet all day teaching or doing housework burns meaningfully more than someone at a desk, even with identical BMRs.
This is the step where honesty matters most. Most of us overestimate our activity. A desk job plus a 20-minute walk is still "lightly active". Picking a level too high inflates your calorie target, and then the scale refuses to move even though you are "following the plan".
Step 3: Adjusting for your goal
Finally, your goal shifts the target:
| Goal | Adjustment |
|---|---|
| Lose weight | Calories set below your TDEE (a deficit) |
| Maintain | Calories set at roughly your TDEE |
| Gain | Calories set above your TDEE (a surplus) |
That final number is what your weekly meal plan is built around — every day's meals, portions, and macros in the My Plan tab add up to it. The plan templates themselves are reviewed by experienced nutritionists, so the calories are distributed across sensible Indian meals rather than dumped into one number you have to figure out yourself.
Why your number differs from other apps
If another app gave you a different target, that is normal, not a bug. Differences come from:
- Different formulas. There are several accepted BMR equations, and they can disagree by 100–200 kcal for the same person.
- Different activity multipliers. One app's "moderately active" is another's "lightly active".
- Different goal adjustments. Apps choose different deficit or surplus sizes.
Every one of these numbers — ours included — is an estimate, a starting point. The truth comes from your own data: log your meals honestly for two to three weeks, do your weight check-ins, and watch the trend in your weekly reports in the Progress tab. If the trend matches your goal, your number is right for you, whatever any calculator says.
When to recalculate
Your calorie target is built on your profile, so update your profile when reality changes:
- Your weight has changed noticeably — after losing or gaining 3–4 kg, your BMR has genuinely shifted, and the old target is stale. This is why weight loss naturally slows over time: a lighter body burns less.
- Your activity has changed — you started a new gym routine, switched from field work to a desk job, or your daily commute changed. Update your activity level, not just your workouts.
- Your goal has changed — switching between lose, maintain, and gain regenerates the target (see "Change your goal").
A practical habit: do your weigh-ins consistently in the app, and whenever the trend crosses a few kilos in either direction, revisit your profile. Small, regular corrections beat one big annual reset.
One caveat: calorie targets from any formula assume a generally healthy adult. If you have a thyroid condition, diabetes, PCOS, are pregnant or breastfeeding, or are managing any medical condition, please have a doctor or registered dietitian confirm your targets before relying on them.
Still stuck? Email contact@diet2fit.com — a human reads every message.