Calorie Calculator
Daily Calorie Calculator estimates how many calories you need each day to maintain, lose, or gain weight — from your sex, age, height, weight, and activity level. No sign-up, and your numbers never leave your browser.
What is the Calorie Calculator?
This calorie calculator estimates how many calories you should eat each day based on your sex, age, height, weight, and how active you are. It returns three numbers at once: your maintenance calories (the amount that keeps your weight steady), a weight-loss target, and a muscle-gain target. Instead of a single figure, you immediately see the range you can choose from depending on your goal. You enter five quick details, you read the result, and you move on. Nothing is uploaded and there is no sign-up.
Everything is calculated locally in your browser, so your age, height, and weight never leave your device. There is no account to create and no data saved — close the tab and your numbers are gone.
How to use it
- Choose your sex, since the calorie formula differs slightly for men and women.
- Pick your unit system: Metric (centimetres and kilograms) or Imperial (feet/inches and pounds). The toggle switches every field at once.
- Type your age, height, and weight.
- Choose an activity level, from sedentary up to extra active.
- Read the results: your daily maintenance calories, the lower target for losing weight, and the higher target for gaining muscle — all updating live as you type.
There is no submit button. Change any input and every number recalculates instantly, so you can see how a different activity level or goal shifts your daily calories in real time.
The formula behind it
This tool uses the Mifflin-St Jeor equation, the formula most dietitians consider the most accurate for everyday use. It first estimates your basal metabolic rate (BMR) — the calories your body burns at complete rest:
- Men: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5
- Women: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age − 161
Your BMR is then multiplied by an activity factor to get your total daily energy expenditure (TDEE), which is your maintenance calorie level:
- Sedentary (little or no exercise): BMR × 1.2
- Lightly active (1–3 days/week): BMR × 1.375
- Moderately active (3–5 days/week): BMR × 1.55
- Very active (6–7 days/week): BMR × 1.725
- Extra active (hard training plus a physical job): BMR × 1.9
For the goal targets, the calculator subtracts about 500 calories per day for steady weight loss (roughly one pound per week) and adds about 300 calories for a conservative lean-muscle surplus.
Examples
- A 30-year-old man, 180 cm and 80 kg, who is moderately active has a BMR of about 1,780 and maintenance calories of about 2,759 — with a weight-loss target near 2,259 and a gain target near 3,059.
- A 28-year-old woman, 165 cm and 60 kg, who is lightly active has maintenance calories of about 1,866, a weight-loss target near 1,366, and a gain target near 2,166.
- A 45-year-old sedentary man, 175 cm and 90 kg, has maintenance calories of about 2,170, with a weight-loss target near 1,670.
Common use cases
- Working out a daily calorie budget before starting a diet or fitness plan.
- Setting a sensible weight-loss target without crash dieting.
- Estimating a small surplus for lean muscle gain in the gym.
- Checking maintenance calories so your weight stays steady.
- Comparing how a change in activity level or body weight changes your daily needs.
Why use this one
Many calorie calculators give you only a single maintenance number. This one shows maintenance, weight loss, and muscle gain side by side, so you can pick the target that matches your goal in one glance. Metric and imperial share a single toggle, so there is no separate page to find. And the whole calculation runs in your browser: results update the instant you type, nothing is sent to a server, there is no account, and the page keeps working offline once it has loaded.
It is part of a small set of body and fitness calculators. The BMR Calculator isolates your resting calorie burn, the TDEE Calculator focuses on total daily energy expenditure, and the Macro Calculator splits a calorie target into grams of protein, carbs, and fat.
Important note
This tool is for general reference and information only and is not medical or nutritional advice. Calorie needs vary with muscle mass, genetics, medical conditions, and daily activity, so treat the figure as a starting estimate and adjust based on how your weight actually changes. For decisions about your diet or health, consult a qualified healthcare professional or registered dietitian.
Frequently asked questions
How many calories should I eat a day?
It depends on your sex, age, height, weight, and how active you are. This tool estimates your maintenance calories (the amount that keeps your weight steady) using the Mifflin-St Jeor equation, then shows roughly 500 calories less for steady weight loss and about 300 more for lean muscle gain.
What formula does this calorie calculator use?
It uses the Mifflin-St Jeor equation to estimate your basal metabolic rate, then multiplies that by an activity factor between 1.2 (sedentary) and 1.9 (very active) to get your total daily energy expenditure, which is your maintenance calorie level.
How do I use the calorie targets to lose weight?
To lose weight at a steady pace of about one pound per week, eat near the weight-loss target, which is roughly 500 calories below your maintenance level. A larger deficit loses weight faster but is harder to sustain and can cost muscle, so most people pick a moderate deficit.
Why is the calorie estimate different from other calculators?
Small differences come from which equation and activity multipliers a calculator uses. These figures are estimates, not exact measurements, because real calorie needs vary with muscle mass, genetics, and day-to-day activity. Treat the number as a starting point and adjust based on how your weight actually changes.
Is my data sent anywhere?
No. The entire calculation runs in your browser. Your age, height, and weight are never uploaded or stored, there is no account to create, and the page keeps working offline once it has loaded.