TDEE Calculator for Bodybuilding
Use Katch-McArdle if you know your body fat % — the most accurate formula for bodybuilders
Why does bodybuilding have specific nutritional needs?
Bodybuilding involves planned cycles of bulk (caloric surplus to maximize muscle gain) and cut (caloric deficit to reveal musculature). The Katch-McArdle formula [¹] is most accurate for bodybuilders because it uses lean mass (FFM) instead of total weight — eliminating the distortion caused by body fat % in standard formulas.
How to calculate your TDEE for bodybuilding
If you know your body fat %, activate the 'Katch-McArdle' option in this calculator. Formula: BMR = 370 + (21.6 × FFM in kg). The resulting TDEE will be more precise than Mifflin-St Jeor especially if you have >15% muscle mass above normal for your height.
Nutrition protocol for bodybuilding: typical phases
| Phase | Duration | Deficit/Surplus | Protein target |
|---|---|---|---|
| Clean bulk | 4-6 months | +200-400 kcal | 1.6-2.0 g/kg |
| Moderate bulk | 3-4 months | +300-500 kcal | 1.6-2.0 g/kg |
| Competitive cut | 12-20 weeks | −400-700 kcal | 2.4-3.1 g/kg |
| Peak week | 7 days | Manipulation | High |
FAQ
1How to use the Katch-McArdle formula?
You need your body fat % to calculate fat-free mass (FFM = weight × (1 - %fat/100)). Then: BMR = 370 + (21.6 × FFM). This formula ignores fat mass weight, which contributes almost nothing to basal metabolism.
2How much protein during competitive cutting?
Helms et al. (2014) [⁸] studies on natural bodybuilders recommend 2.3-3.1 g/kg of lean mass during competitive cutting. This higher range compensates for the catabolic pressure of severe deficit.
3What are refeed days and when to use them?
Refeed days are days at maintenance or slightly higher intake with high carbs, interspersed during cutting. Goals: replenish glycogen, reduce fatigue, normalize leptin and T3. Recommended 1-2 times/week during extended cuts (>8 weeks).
4What supplements does evidence-based bodybuilding use?
Evidence A: creatine monohydrate (3-5 g/day), caffeine (3-6 mg/kg), protein. Evidence B: beta-alanine (3-6 g/day), citrulline malate (6-8 g/day). No solid evidence: BCAAs if total protein is sufficient, most 'fat burners'.