About
Welcome to calorie-calculator.org — a simple, accurate calorie calculator built by our family for families like yours.
Last updated: October 2025
Why We Built This
We started calorie-calculator.org because our family wanted a calorie calculator that was accurate, easy to use, and went beyond a single number. We wanted the context that actually helps you act on the results — things like macronutrient splits, BMR, TDEE, safety floors, and clear targets for losing, maintaining, or gaining weight.
So we combined trusted equations with clean design and practical guidance. The goal: help you understand calories, build better habits, and make steady progress toward better health — without guesswork.
About This Site
- Free to use. No account required. Results render server-side for fast loads and shareable links.
- Transparent math. We show which formulas are used and how we apply the activity multipliers to estimate TDEE.
- Actionable outputs. Along with maintenance calories, we display deficit/surplus targets and multiple macro presets so you can pick a plan that fits your style of eating.
Have feedback or found a bug? We’d love to hear from you. Contact us.
Formulas We Use
At its core, the calculator estimates your BMR (Basal Metabolic Rate) and then multiplies by an activity factor to estimate TDEE (Total Daily Energy Expenditure). We support three BMR equations:
Mifflin–St Jeor
Our default because it tends to perform well for most modern populations.
For men: BMR = 10 × kg + 6.25 × cm − 5 × age + 5 For women: BMR = 10 × kg + 6.25 × cm − 5 × age − 161
Katch–McArdle
Used when you provide body-fat %. This formula relies on lean body mass and can be more reflective for trained individuals.
LBM (kg) = weight_kg × (1 − bodyfat_% / 100) BMR = 370 + 21.6 × LBM
Harris–Benedict (revised)
Included for completeness. We use the 1984 revisions.
Men: BMR = 88.362 + (13.397 × kg) + (4.799 × cm) − (5.677 × age) Women: BMR = 447.593 + (9.247 × kg) + (3.098 × cm) − (4.330 × age)
Activity Factors → TDEE
TDEE is estimated by multiplying BMR by a standard multiplier based on your typical activity:
| Level | Multiplier | Typical description |
|---|---|---|
| Sedentary | 1.2 | Little or no exercise |
| Light | 1.375 | 1–3 days/week of light activity |
| Moderate | 1.55 | 3–5 days/week of moderate activity |
| Active | 1.725 | 6–7 days/week or physical job |
| Very Active | 1.9 | Hard training plus physical job |
Macronutrients
After estimating your calorie target, we provide several macro presets (protein / fat / carbs). Protein and carbs are estimated at 4 kcal/gram, fat at 9 kcal/gram. Presets are intended as starting points—adjust based on preference, satiety, training, and results.
Notes & Disclaimers
- Results are estimates. Individual energy needs vary due to genetics, hormones, sleep, stress, and measurement error.
- Calorie targets below common safety floors are hidden to promote reasonable, sustainable plans.
- For medical conditions, pregnancy, breastfeeding, or eating-disorder history, consult a qualified professional before making major dietary changes.
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