Quick Answer
Enter your sex, age, height, weight and activity level in the calculator below to get your daily calorie needs.
The tool returns four numbers: BMR (calories at rest), TDEE for maintenance, a fat-loss target (−500 kcal) and a muscle-gain target (+300 kcal).
It uses the Mifflin-St Jeor equation, the modern standard for resting metabolic rate.
What is a calorie calculator?
A calorie calculator estimates your Total Daily Energy Expenditure (TDEE), the total energy your body burns over 24 hours.
Knowing this number turns weight loss, maintenance and muscle gain from guesswork into a math problem.
How the calculation works
The tool follows two steps. First it calculates your BMR with Mifflin-St Jeor, then it multiplies BMR by an activity factor to estimate your real-world burn.
- Step 1: calculate BMR, the calories you burn at complete rest.
- Step 2: multiply BMR by an activity factor (1.2 to 1.9) to get TDEE.
- Step 3: apply ±500 or +300 kcal for your goal.
Calorie Calculator
Mifflin-St Jeor with maintenance, fat-loss, and gain targets.
Get your personalised daily energy needs in one tap, with targets for every goal.
Activity multipliers explained
Most people overestimate their activity. Pick conservatively and adjust upward only if your weight stalls.
| Level | Multiplier | Who it suits |
|---|---|---|
| Sedentary | 1.20 | Desk job, little to no intentional exercise |
| Lightly Active | 1.375 | Light exercise 1 to 3 days a week |
| Moderately Active | 1.55 | Moderate exercise 3 to 5 days a week |
| Very Active | 1.725 | Hard exercise 6 to 7 days a week |
| Extra Active | 1.90 | Physical job plus hard training |
The math of weight loss
One kilogram of body fat stores roughly 7,700 calories. The size of your daily deficit decides how fast you lose.
| Daily deficit | Weekly fat loss | Use case |
|---|---|---|
| −250 kcal | ~0.25 kg | Slow, very sustainable |
| −500 kcal | ~0.5 kg (1 lb) | Recommended default |
| −750 kcal | ~0.7 kg | Faster, watch protein and sleep |
| −1,000 kcal | ~1.0 kg (2 lb) | Aggressive, short term only |
Safety minimums
Eating too little for too long slows metabolism and risks nutrient deficiencies. Without medical supervision, do not drop below these floors.
- Women: 1,200 kcal/day minimum.
- Men: 1,500 kcal/day minimum.
How to actually succeed
- Prioritise protein: 1.6 to 2.2 g per kg of bodyweight protects muscle in a deficit.
- Use a kitchen scale: measuring cups overshoot by 20 to 40% on dense foods.
- Recalculate every 5 kg: as you shrink, so does your TDEE.
- Sleep 7 to 9 hours: poor sleep raises ghrelin and tanks adherence.
Methodology
BMR is calculated with the Mifflin-St Jeor equation.
- Men: (10 × weight in kg) + (6.25 × height in cm) − (5 × age) + 5
- Women: (10 × weight in kg) + (6.25 × height in cm) − (5 × age) − 161
- TDEE: BMR × activity factor (1.2 to 1.9)
- Fat loss: TDEE − 500 kcal
- Muscle gain: TDEE + 300 kcal
Imperial inputs are converted to metric internally before calculation.
Frequently asked questions
How do I calculate my calories accurately?
Use a tool that runs Mifflin-St Jeor with your real age, sex, height and activity. The calculator above does exactly that. Track for two weeks and adjust if your scale weight does not match the math.
Is 300 kcal the same as 300 calories?
Yes. The "Calories" on food labels are technically kilocalories (kcal). 1 Calorie equals 1 kcal equals 1,000 small calories.
How many calories is 1 kg of fat loss?
About 7,700 kcal. A daily deficit of 500 kcal works out to roughly 0.5 kg of fat loss per week.
How many calories should a 70 kg person eat?
It depends on height, age and activity. A 70 kg sedentary office worker may need 1,800 kcal to maintain, while a 70 kg endurance athlete might need 3,000+.
What is the minimum calories per day to lose weight?
Most health bodies recommend 1,200 kcal as a floor for women and 1,500 kcal for men, unless you are under medical supervision.
How much protein should I eat on a 1,200 kcal diet?
Aim for 1.6 to 2.2 g per kg of bodyweight. On 1,200 kcal that means anchoring every meal around a protein source to stay full.
How do I track the calories of my food?
Pair a kitchen scale with an app like MyFitnessPal or Cronometer. The scale removes the guesswork that derails most cuts.
What activity level should I pick?
Underestimate. If you exercise inconsistently, choose Sedentary or Light. You can always shift up after two weeks of data.
Should I eat back my exercise calories?
Generally no. Wearables can overestimate burn by 30 to 50%, and your activity factor already includes training.
Why did my weight loss plateau?
As you lose weight your body needs less energy. If the scale stalls for more than two weeks, recalculate using your new bodyweight and adjust intake by 100 to 200 kcal.
Is my data safe?
Yes. The calculation runs entirely in your browser. Nothing is stored or sent to a server.
Related calculators
- BMR and TDEE, see the burn this calorie target is built on.
- Macro Split Calculator, turn your calorie target into protein, carbs and fat.
- Body Fat Calculator, track composition, not just bodyweight.
- Water Intake Calculator, daily hydration target alongside food.
Medical disclaimer
This calculator and article are for general educational purposes only and are not medical advice. Calorie targets are population estimates and should not be used to drive aggressive deficits. Do not eat below roughly 1,200 kcal a day (women) or 1,500 kcal a day (men) without supervision from a qualified healthcare professional.
If you have a history of disordered eating or are recovering from one, please do not use a calorie tool without support. In the UK contact Beat, in the US contact the National Eating Disorders Association, or speak to your doctor.
See the full site-wide Disclaimer & Notice for the complete terms that apply to every calculator and tool on dmbio.
