Losing Weight Sustainably: How to Actually Set a Calorie Target
A complete walkthrough from BMR to TDEE to a real daily calorie target, showing how each calculation builds on the last.
Most calorie targets people pick are guesses. The actual calculation is a short chain of three formulas, each building on the last, that turns body stats into a specific, defensible number.
Step 1: BMR — your calorie floor at complete rest
Using the Mifflin-St Jeor equation for a 34-year-old man, 85kg, 180cm: BMR = 10×85 + 6.25×180 − 5×34 + 5 = 850 + 1,125 − 170 + 5 = 1,810 kcal/day — the energy cost of simply existing for 24 hours, before any activity is added.
Step 2: TDEE — adding real-world activity
Multiplying BMR by an activity factor (1.55 for moderately active, exercising 3-5 days/week): 1,810 × 1.55 ≈ 2,806 kcal/day. This is the calorie level at which weight would be expected to stay roughly stable — the actual maintenance number, not the resting-only BMR figure many people mistakenly use as their baseline.
Step 3: applying a deficit for weight loss
Targeting a loss of 0.5kg per week requires a daily deficit of roughly 0.5 × 7,700 ÷ 7 ≈ 550 kcal/day below TDEE: 2,806 − 550 ≈ 2,256 kcal/day target — a specific, calculated number rather than an arbitrary round figure like "eat 2,000 calories."
Step 4: turning the target into macros, not just a total
A 2,256 kcal target split 30% protein / 40% carbs / 30% fat: protein = (2,256×0.30)/4 ≈ 169g, carbs = (2,256×0.40)/4 ≈ 226g, fat = (2,256×0.30)/9 ≈ 75g. Having gram targets, not just a calorie total, makes the plan concretely trackable against real food labels.
Why each step matters, and what happens if you skip one
Skipping straight from body stats to "eat less" without calculating TDEE risks setting an arbitrary deficit that's either too aggressive (unsustainable, often triggering rebound overeating) or too mild (frustratingly slow progress). Calculating the actual maintenance level first, then applying a modest, sustainable deficit on top of it, is what separates a calculated plan from a guess.
A note on adjusting over time
As weight changes, BMR changes too (a lighter body burns somewhat fewer calories at rest), which is exactly why this full four-step calculation is worth re-running every several weeks rather than treating the initial target as fixed for months at a time.
Calculate your own numbers with the BMR calculator, TDEE calculator, calorie calculator, and macro calculator.