Daily Calorie Calculator (TDEE)
Find your personalised daily calorie target for weight loss, maintenance, or muscle gain — calculated from Mifflin-St Jeor BMR plus your activity level.
TL;DR
Enter your stats and goal. The calculator returns your TDEE (maintenance) plus a goal-adjusted target. Weight loss: deficit of 15–20%. Muscle gain: surplus of 10–15%. Nothing is sent anywhere — all maths runs in your browser.
Calculate
🔒 Calculations happen in your browser. Nothing is sent or stored.
What is TDEE?
TDEE (Total Daily Energy Expenditure) is the total number of calories you burn in a day — accounting for your resting metabolism (BMR), physical activity, and the thermic effect of food. It is the number you need to know before setting any calorie target.
How is TDEE calculated?
TDEE = BMR × activity multiplier
We first calculate BMR using the Mifflin-St Jeor formula (1990, most accurate for modern populations), then multiply by your activity level:
- 1.2 — Sedentary: desk job, fewer than 2 workouts per week
- 1.375 — Lightly active: 1–3 light workouts or walks per week
- 1.55 — Moderately active: 3–5 structured sessions per week
- 1.725 — Very active: 6–7 hard sessions per week
- 1.9 — Extra active: athlete, physical job, or twice-daily training
Calorie targets by goal
Weight loss
A healthy rate of fat loss is 0.5–1 kg per week, requiring a deficit of roughly 500–700 kcal/day. In practice, start at 15–20% below TDEE and reassess after 3–4 weeks. Never eat below BMR × 1.1 — prolonged restriction triggers adaptive thermogenesis, slowing your metabolism.
KeplerFit scales the deficit by BMI: 12% deficit for BMI under 25, 18% for 25–30, 22% for BMI over 30 — protecting lean mass at every stage.
Maintenance
Eat at TDEE. Useful during a training programme where weight stability is the goal, or as a diet break to reset leptin after a long cut.
Muscle gain (lean bulk)
A modest surplus of 10–15% above TDEE (roughly 250–400 kcal/day) maximises muscle protein synthesis without excessive fat gain. Aim for 0.25–0.5 kg body-weight gain per week; faster progress is mainly fat.
Protein matters at every goal
Regardless of whether you are cutting, maintaining, or bulking, aim for 1.6–2.2 g of protein per kg of body weight per day. Protein preserves muscle during a deficit and supports muscle repair and growth during a surplus. Prioritise protein within your calorie budget before adjusting carbs and fat.
Not medical advice. These are population-level estimates. Individual needs vary. People with metabolic conditions, eating disorders, or specific medical history should consult a registered dietitian before changing calorie intake.
Frequently asked questions
How many calories do I need per day?
Your TDEE depends on BMR and activity level. Enter your numbers above for a personalised result. A typical moderately-active 30-year-old woman (165 cm, 65 kg) has a TDEE of roughly 1,900–2,100 kcal.
How many calories should I eat to lose weight?
Aim for 15–20% below your TDEE. For most people that is 300–500 kcal/day below maintenance, yielding 0.5–1 kg/week. Slower is safer: muscle is preserved, the deficit is easier to sustain.
How many calories to gain muscle?
Eat 10–15% above TDEE (250–400 kcal surplus). Combined with progressive resistance training and adequate protein (1.6–2.2 g/kg), this supports lean muscle gain of 0.25–0.5 kg/week.
What is a calorie deficit?
Eating fewer calories than you burn (TDEE). A 500 kcal/day deficit theoretically removes ~0.5 kg of fat per week. In reality, some water and a small amount of lean tissue are also lost — higher protein intake minimises the lean-mass cost.
Can I go below my BMR?
It is not recommended. Sustained eating below BMR triggers adaptive thermogenesis — your body reduces its own resting burn, making further progress harder. KeplerFit enforces a dynamic floor of BMR × 1.10 to prevent this.
Related tools
Calories calculated. Now track them automatically.
KeplerFit uses your TDEE to build a personal nutrition plan. Snap a food photo and the AI counts the calories — no manual logging. Free to start.
Download on Google Play