Calculator
Enter your details, pick an activity level, then set a weekly goal. The tool estimates maintenance calories and the daily deficit or surplus.
Example data table
| Sex | Age | Height | Weight | Activity | Goal | Weekly rate | Estimated target |
|---|---|---|---|---|---|---|---|
| Male | 30 | 175 cm | 75 kg | Moderate | Lose | 0.5 kg/week | ~2,100 kcal/day |
| Female | 28 | 165 cm | 62 kg | Light | Maintain | 0 | ~1,900 kcal/day |
| Male | 35 | 5 ft 10 in | 185 lb | Active | Gain | 0.5 lb/week | ~3,000 kcal/day |
Values are illustrative only. Your actual needs can differ.
Formula used
1) Basal Metabolic Rate (BMR)
Mifflin–St Jeor equation:
- Male: BMR = 10·kg + 6.25·cm − 5·age + 5
- Female: BMR = 10·kg + 6.25·cm − 5·age − 161
2) Maintenance calories (TDEE)
TDEE = BMR × activity multiplier
3) Daily deficit or surplus
Convert weekly rate to calories using an energy approximation:
Daily change = (rate_kg_per_week × 7700) ÷ 7
4) Target calories
- Loss: Target = TDEE − daily deficit
- Gain: Target = TDEE + daily surplus
- Maintain: Target = TDEE
How to use this calculator
- Pick units and enter age, height, and weight.
- Select your activity level to estimate maintenance calories.
- Choose a goal and weekly rate, or set maintenance.
- Optionally enable macros for daily protein, fat, and carbs.
- Click Calculate, then download CSV or PDF if needed.
FAQs
1) What is a calorie deficit?
A calorie deficit happens when you eat fewer calories than you burn. Over time, the body uses stored energy to cover the gap, which can reduce body weight. The tool estimates that daily gap from your goal rate.
2) How accurate is the maintenance estimate?
It is an estimate based on population formulas and an activity multiplier. Real needs vary with body composition, step count, training volume, sleep, stress, and tracking errors. Use it as a starting point, then adjust using trends.
3) What weekly rate is reasonable?
Many people do well with modest changes, such as 0.25–0.75 kg per week, depending on starting size and training. If performance, mood, or recovery drops, reduce the deficit or slow the rate.
4) Why does the calculator use 7,700 calories per kg?
It is a common approximation for the energy content of body fat. Real weight change includes water, glycogen, and lean tissue. Your actual deficit-to-scale result can differ, especially in the first two weeks.
5) Can I use a custom maintenance number?
Yes. If you track intake and bodyweight consistently, you may know your true maintenance better than a formula. Enter it to make the target more personalized and reduce reliance on generic multipliers.
6) Do macro targets guarantee results?
No. Macros are a planning aid. Protein supports satiety and muscle, fat supports hormones, and carbs support training. Results still depend on calorie consistency, food choices, sleep, and how accurately intake is tracked.
7) What if the target calories feel too low?
First, reduce the weekly loss rate or increase activity gradually. Also review your activity selection and portion tracking. If the tool suggests very low intake, seek qualified medical guidance before cutting further.
8) Should I eat the same calories every day?
Not required. Many people keep a weekly average, eating slightly more on training days and less on rest days. The key is the average over time and consistent protein intake and recovery habits.