Calorie & Macro Calculator — Daily Calories, BMR & TDEE Free

How to Use the Calorie & Macro Calculator

You can get a full nutrition target in under a minute. Here is exactly what to do:

1. Enter age and gender — These adjust the Mifflin-St Jeor BMR equation.
2. Enter weight and height — Use kilograms and centimetres (e.g. 70 kg and 170 cm).
3. Pick activity level — Be honest; most desk workers are sedentary or lightly active.
4. Choose your goal — Maintain, lose (≈ −20% calories), or gain (≈ +15%).
5. Click Calculate — Read daily calories, BMR, TDEE, and protein/carbs/fat in grams.

Example: A 30-year-old man, 70 kg, 170 cm, moderately active (1.55), goal maintain:

• BMR ≈ 1,618 kcal
• TDEE ≈ 2,508 kcal
• Balanced macros ≈ 188 g protein / 251 g carbs / 84 g fat (30/40/30)

Same person with goal lose: target ≈ 2,006 kcal (80% of TDEE). All math runs privately in your browser.

What Are BMR, TDEE & Macros — and Why They Matter

BMR (Basal Metabolic Rate) is the energy your body burns at complete rest — breathing, circulating blood, and maintaining organs. It is usually 60–70% of total daily burn for sedentary people. Two people of the same weight can have different BMRs if height, age, or sex differ — that is why the Mifflin-St Jeor inputs matter.

TDEE (Total Daily Energy Expenditure) adds movement: walking, training, fidgeting, and work. We estimate it by multiplying BMR by an activity factor. Eat near TDEE to maintain weight; below it to lose; above it to gain. A rough rule from energy balance: about 3,500 kcal ≈ 0.45 kg (1 lb) of body fat in theory, but real-world loss is rarely linear week to week because of water and glycogen.

Macros are the three calorie-providing nutrients:

Calories set the scale trend; macros shape how that energy is distributed. A cut with higher protein often feels more filling than the same deficit with very low protein. Athletes may prefer more carbs around workouts (our bulk split raises carbs to ~45%). Keto-style eating pushes most calories into fat (~70%) while keeping carbs near ~5% — useful only if you actually follow that style consistently.

Who benefits most from this calculator? People starting a cut or bulk who need a number to log against; coaches explaining BMR vs TDEE; and anyone comparing balanced vs keto/cut/bulk pages on SnapCalc. If you already know your maintenance from months of careful tracking, prefer that measured TDEE over any equation.

Use this tool as a starting estimate, then adjust every 1–2 weeks based on weight trend, hunger, and performance — not as a rigid lifelong prescription. Pair it with body-composition context from BMI or body-fat estimates when goals are aesthetic or athletic.

The Mifflin-St Jeor Formula with a Worked Example

Men:

BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5

Women:

BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age − 161

Step-by-step (man, 70 kg, 170 cm, age 30, activity 1.55, maintain):

• BMR = 10×70 + 6.25×170 − 5×30 + 5 = 700 + 1,062.5 − 150 + 5 = 1,617.5 → 1,618 kcal (rounded)
• TDEE = 1,618 × 1.55 = 2,507.9 → 2,508 kcal
• Balanced 30/40/30 at 2,508 kcal → protein 188 g, carbs 251 g, fat 84 g

Goal adjustments used by this calculator:

Macro split reference:

At 2,000 kcal cut (40/30/30): protein = (2,000×0.40)/4 = 200 g; carbs = (2,000×0.30)/4 = 150 g; fat = (2,000×0.30)/9 = 67 g.

Second worked example (woman, cut): Age 28, 62 kg, 165 cm, lightly active (1.375), goal lose, balanced page.

• BMR = 10×62 + 6.25×165 − 5×28 − 161 = 620 + 1,031.25 − 140 − 161 = 1,350.25 → 1,350 kcal
• TDEE = 1,350 × 1.375 = 1,856 kcal
• Cut target = 1,856 × 0.80 ≈ 1,485 kcal
• Balanced (cut) split on the balanced page uses ~35/35/30 → protein ≈ 130 g, carbs ≈ 130 g, fat ≈ 50 g

Open the dedicated Cut variation if you want the stricter 40/30/30 protein-forward pie instead. The bar chart always shows grams so you can see absolute changes when weight or activity changes; the pie mainly changes when the diet percentage split changes.

Important Limitations & Common Mistakes

Avoid these pitfalls:

• Inflating activity: Choosing “very active” when you train 3×/week desk-bound overestimates TDEE by hundreds of calories. When unsure, pick the lower multiplier for two weeks and review the scale trend.
• Expecting exact scale math: Water, sodium, and glycogen swing daily weight 1–2 kg. Judge averages over 2 weeks, not single mornings.
• Ignoring protein quality and micronutrients: Hitting macro grams on ultra-processed food still leaves fiber, vitamin, and mineral gaps.
• Aggressive deficits: Going far below 80% of TDEE can tank energy and adherence. Pair calorie targets with your BMI and body fat context.
• Copying someone else’s macros: A 90 kg lifter’s bulk numbers are not a template for a 55 kg beginner. Recalculate when weight changes by ~5 kg or activity changes long-term.
• Treating estimates as medical advice: Pregnancy, illness, eating disorders, and clinical diets need a qualified professional — not a web calculator alone.

If progress stalls after 2–3 weeks of consistent logging, adjust by about 100–200 kcal or revisit activity — do not slash intake repeatedly without a plan for protein and recovery.

Related Tools

• BMI Calculator — Check body mass index and healthy weight range
• Body Fat Calculator — Estimate body fat % with the US Navy method