Every fat-loss conversation eventually arrives at the same question: "What is my TDEE so I can eat below it?" Run your weight, height, age, sex, and activity level through any TDEE calculator and you get a number. But the number on its own does not lose weight. The protocol around it does.

Step 1 — Get Your TDEE Number Right

Use the Mifflin-St Jeor equation (the most accurate predictive method available without lab equipment). Be honest about your activity level — this is where 80% of TDEE calculators get wrecked. A useful guideline:

  • Sedentary (1.2) — Desk job, less than 5,000 steps/day, no formal training.
  • Light (1.375) — Desk job + 1–3 short training sessions/week, or 7,000–10,000 daily steps.
  • Moderate (1.55) — 3–5 training sessions/week + 8,000+ daily steps.
  • Heavy (1.725) — Physical job or 6+ training sessions/week.

When in doubt, round down. Cutting on an inflated TDEE is the #1 reason people stall.

Step 2 — Set a Sane Deficit

Research from Helms et al. (2014) on natural physique athletes pinpoints the deficit sweet spot:

  • Aggressive cut: ~0.7–1.0% of bodyweight per week (TDEE − 500 to 750 kcal).
  • Standard cut: ~0.5% per week (TDEE − 400 kcal). Best for most lifters.
  • Mini-cut / lean recomp: ~0.25% per week (TDEE − 200 kcal). Slow but virtually no muscle loss.

Steeper deficits than 1% per week accelerate muscle loss and tank training quality. Patience pays.

Step 3 — Lock In Protein and Macros

In a deficit, protein is non-negotiable. Three rules:

  • Protein: 1.8 – 2.4 g per kg of bodyweight. Higher end if you are lean (under 15% BF) or in an aggressive cut.
  • Fat: Minimum 0.7 g/kg to preserve hormones.
  • Carbs: Fill the rest of your calorie budget.

Plug your cut calories into our Macro Matrix with a "Fat Loss" goal to get the gram-by-gram breakdown.

Step 4 — Track Weekly, Adjust Bi-Weekly

This is the step everyone skips and the one that decides whether the cut works:

  1. Weigh yourself every morning, fasted, post-bathroom.
  2. Each Sunday, average the past 7 days. That number is your weekly weight.
  3. After 2 weeks, compare to your starting weight:
    • Lost as expected (0.5–1% bodyweight) → hold course.
    • Lost less than 0.3% → drop calories by another 150 kcal.
    • Lost more than 1.2% → eat 150 kcal more, you are cutting too hard.
  4. Repeat the 2-week review until goal is reached.

What to Expect Over 12 Weeks

A well-set-up cut for a typical 80 kg lifter looks like this:

  • Weeks 1–2: 1.5–2.5 kg loss (much of it water and glycogen). Do not get euphoric.
  • Weeks 3–8: 0.4–0.6 kg/week of mostly fat. Strength should hold within ±5%.
  • Weeks 9–12: Loss may slow to 0.3 kg/week as TDEE drops adaptively. Diet break (1 week at maintenance) helps.

Total expected loss for 12 weeks: ~5–7 kg, with minimal lean mass loss.

Common TDEE Cut Mistakes

  • Overestimating activity level — Default to one bracket lower.
  • Eyeballing portions — Use a food scale for week 1 to calibrate.
  • Re-running TDEE only at the start — Recalculate every 4 weeks; TDEE drops as bodyweight drops.
  • Cutting protein to fit calories — Protect protein at all costs; cut carbs or fats instead.

Bottom Line

A TDEE calculator is a starting hypothesis. The 4-step loop — measure honestly, set a sane deficit, lock protein, calibrate every two weeks — is what turns the number into actual results. Run your starting numbers in our TDEE Calculator, then come back here for the protocol.