How many calories do you need a day? This free calorie calculator estimates your maintenance calories and offers gentle, sustainable targets for losing or gaining weight – with a safe-minimum guardrail, not crash-diet numbers.
Estimates only, for general guidance. Gradual changes (around 0.25-0.5 kg/week) are usually more sustainable than rapid ones. Very low-calorie diets aren’t recommended without medical supervision – for a personalised plan, see a dietitian or doctor.
How the Calorie Calculator Works
This tool estimates your maintenance calories (TDEE), then adjusts that number for a chosen goal of losing, maintaining, or gaining weight — using a gentle deficit or surplus rather than crash-diet numbers, plus a safe-minimum guardrail so a loss target never drops too low.
Formula: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + (5 if male, −161 if female) [Mifflin-St Jeor equation]. TDEE = BMR × activity factor (1.2 to 1.9 depending on activity level). Target calories: Maintain = TDEE; Lose = TDEE − 500 (floored at 1,500 kcal for men or 1,200 kcal for women — if TDEE − 500 would fall below that floor, the floor value is shown instead); Gain = TDEE + 300. Imperial inputs convert first: height(cm) = (feet × 12 + inches) × 2.54, weight(kg) = pounds × 0.45359237.
- Sex — male or female, changes the BMR constant (+5 or −161) and the safe-minimum floor (1,500 or 1,200 kcal).
- Age — your age in years.
- Height — in centimeters (metric) or feet and inches (imperial).
- Weight — in kilograms (metric) or pounds (imperial).
- Activity level — sedentary through extra active, each with its own multiplier applied to BMR.
- Goal — lose, maintain, or gain, which determines whether 500 kcal is subtracted, nothing changes, or 300 kcal is added.
Example Scenarios
| Sex | Age | Height | Weight | Activity | Goal | Target Calories (kcal/day) |
|---|---|---|---|---|---|---|
| Male | 30 | 178 cm | 75 kg | Moderately active | Maintain | 2,662 |
| Male | 30 | 178 cm | 75 kg | Moderately active | Lose | 2,162 |
| Male | 30 | 178 cm | 75 kg | Moderately active | Gain | 2,962 |
| Female | 50 | 160 cm | 55 kg | Sedentary | Lose | 1,200 (floor applied) |
| Female | 28 | 165 cm | 58 kg | Lightly active | Lose | 1,301 |
| Male | 45 | 182 cm | 95 kg | Very active | Gain | 3,521 |
Calorie Calculator FAQ
How is my calorie target calculated from my TDEE?
The calculator first estimates your maintenance calories (TDEE) from your BMR and activity level. For weight loss it subtracts about 500 kcal, for weight gain it adds about 300 kcal, and for maintenance it uses your TDEE unchanged.Why is there a minimum calorie floor for weight loss?
The calculator won’t show a loss target below 1,500 kcal for men or 1,200 kcal for women, even if subtracting 500 kcal from your TDEE would go lower. Very low-calorie intakes aren’t recommended without medical supervision, so a safe-minimum figure is shown instead with a note to speak with a dietitian or doctor.How much weight will a 500-calorie daily deficit lose per week?
A roughly 500 kcal/day deficit is generally associated with about 0.45 kg (1 lb) of weight loss per week, since that’s approximately the energy value of a pound of body fat. Actual results vary by individual and tend to slow over time.What if I want to gain weight instead of lose it?
Selecting the Gain goal adds a gentle surplus of about 300 kcal per day on top of your maintenance calories, intended for gradual weight gain. Pairing this surplus with strength training is commonly suggested to support more muscle gain relative to fat.Is the 1,200 / 1,500 kcal safety floor always the right minimum for me?
No — these are general guardrail figures, not personalized medical minimums. Actual safe intake varies by individual factors like body size, activity, and health conditions, so anyone considering a very low-calorie intake should get personalized guidance from a dietitian or doctor.Does this calculator account for muscle mass or body composition?
No. It uses the Mifflin-St Jeor equation, which estimates BMR from age, sex, height and weight only — it doesn’t account for muscle mass, body fat percentage, or other individual factors, so treat the result as a general estimate rather than an exact figure.Related Calculators
To dig deeper into your energy needs, compare this against the TDEE calculator for your baseline maintenance number, plan your macros with the macro calculator, or map out a gradual plan with the weight loss timeline calculator.