Calorie calculator inputs
Formula used
The calculator starts with basal metabolic rate. Mifflin-St Jeor uses weight, height, age, and sex. For men, BMR equals 10 × weight kg + 6.25 × height cm − 5 × age + 5. For women, BMR equals 10 × weight kg + 6.25 × height cm − 5 × age − 161.
The revised Harris-Benedict option uses older activity research. Katch-McArdle uses lean mass. Lean mass equals weight × (1 − body fat percentage). Its BMR formula is 370 + 21.6 × lean mass kg.
Maintenance calories equal BMR × activity multiplier, plus any workout calories you choose to eat back. Weight loss or gain uses the common 7,700 calories per kilogram estimate. Target calories equal maintenance plus the selected daily adjustment.
How to use this calculator
Pick your unit system first. Enter age, height, weight, and sex. Choose the formula you trust most. Use Mifflin-St Jeor for most adults. Use Katch-McArdle when you know body fat percentage.
Select an activity level that describes your normal week. Then choose a goal. Enter a weekly change target for loss or gain. Use custom adjustment when a coach gave you a fixed calorie deficit or surplus.
Add workout details only when they are not already included in your activity choice. Set macro preferences. Submit the form. Review the daily calories, maintenance estimate, macro targets, meal target, and food label result.
Calorie planning guide
Why daily calories matter
Calories measure food energy. Your body uses that energy for breathing, movement, digestion, training, thinking, and recovery. A good calorie estimate gives structure to eating. It does not need to be perfect. It needs to be useful, repeatable, and close enough to guide decisions.
This tool separates basic metabolism from activity. That helps you see why two people with the same weight may need different intakes. Height, age, sex, muscle mass, steps, job type, and workouts all change the result. The output is a starting point, not a fixed rule.
Choosing the right formula
Mifflin-St Jeor is a strong default for many adults. It often gives realistic estimates for modern lifestyles. Revised Harris-Benedict may read higher for some people. Katch-McArdle can be helpful for athletes or lifters who know body fat percentage. It uses lean body mass, so the body fat input should be honest.
Activity choice has a large effect. Sedentary means limited movement beyond daily tasks. Light activity fits walking and a few easy sessions. Moderate activity fits regular training. Very active fits hard sessions, physical work, or high daily steps. Pick the level that matches most weeks, not your best week.
Turning calories into action
For weight loss, a moderate deficit is easier to maintain. Large deficits can increase hunger and reduce training quality. For weight gain, a small surplus can support muscle growth while limiting excess fat. The weekly change field turns your goal into a daily adjustment using an energy balance estimate.
Macros add useful detail. Protein supports fullness and muscle repair. Fat supports hormones and helps meals feel satisfying. Carbohydrates fuel training and busy days. The calculator sets protein from body weight, fat from calorie percentage, and leaves the rest for carbohydrates.
Tracking and adjusting
Use the result for two to four weeks. Track body weight trends, energy, hunger, sleep, and training. Daily scale changes are noisy. Weekly averages are better. If your trend does not move as expected, adjust calories by 100 to 200 per day.
The food label section helps with portions. Enter calories per serving, label serving size, and amount eaten. This is useful for cereals, rice, sauces, snacks, drinks, and cooked meals. Consistent measuring teaches portion awareness. Over time, you may need fewer calculations.
No calculator can know every detail. Illness, medications, stress, menstrual cycle changes, sleep loss, and water retention can shift results. Use the numbers as guidance. Pair them with real progress data. A steady plan usually beats a perfect plan that is too hard to follow.
A review routine improves accuracy. Weigh similar foods the same way. Record meals before eating when possible. Keep notes on weekends, sauces, drinks, and snacks. These small items often explain stalled progress. When life gets busy, return to the basic target. Consistency across average weeks matters more than perfect single days for steady reliable long-term results overall.
Frequently asked questions
1. What is the best formula for daily calories?
Mifflin-St Jeor is a strong default for many adults. Katch-McArdle can be better when you know body fat percentage. Harris-Benedict is useful for comparison, but it may estimate higher for some users.
2. What does BMR mean?
BMR means basal metabolic rate. It estimates calories your body uses at rest for basic functions. It does not include workouts, walking, work, or planned activity.
3. What does TDEE mean?
TDEE means total daily energy expenditure. It starts with BMR and multiplies it by an activity level. This gives an estimate of maintenance calories for your usual day.
4. Should I eat back workout calories?
Eat them back only when your activity multiplier does not already include training. Many people start with 0% to 50%. Then they adjust based on weight trend, hunger, and workout performance.
5. How fast should I lose weight?
A steady goal is usually easier than an extreme one. Many people choose a small or moderate weekly change. Very fast loss can increase hunger and may reduce training quality.
6. How fast should I gain weight?
A small surplus is often enough for gradual gain. It may support muscle growth while limiting unnecessary fat gain. Track strength, measurements, and weekly weight averages.
7. Why is body fat percentage optional?
Only the Katch-McArdle formula needs body fat percentage. If you do not know it, use Mifflin-St Jeor. Guessing body fat can make the lean mass estimate less reliable.
8. Are macro targets required?
No. Calories drive the main energy target. Macros help improve food quality, fullness, and performance. Protein, fat, and carbohydrates can be adjusted for preference and training needs.
9. Why does activity level change results so much?
Movement can add many calories each day. Steps, work demands, chores, and exercise all matter. Pick the activity level that matches your normal week, not an unusually active week.
10. Can this calculate food label calories?
Yes. Enter calories per serving, label serving size, and the amount eaten. The calculator scales the calories to match your actual portion size.
11. When should I change my calorie target?
Review progress after two to four weeks. Use weekly averages instead of daily weight changes. Adjust by 100 to 200 calories if your trend is not moving as expected.