Calorie Calculator Online
Estimate the calories you need each day to maintain, lose, or gain weight, computed in your browser. A general estimate, not medical advice.
The Calorie Calculator runs entirely in your browser and the stats you enter never leave your device. It is a general estimate from a standard formula, not medical advice.
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About Calorie Calculator
Calorie Calculator estimates how many calories you need each day to maintain your current weight, and how many to eat if you want to lose or gain weight instead. It combines your weight, height, age, and sex with the Mifflin-St Jeor formula to estimate resting energy use, scales that by your activity level to get maintenance calories, then adjusts the total for a mild or standard calorie deficit or surplus depending on your goal. Enter your stats in metric or US units, pick an activity level and a goal, and see your maintenance and target calories update instantly, along with the rough weekly weight change that target implies. This is a general estimate from a standard formula, not medical advice, so treat the numbers as a starting point rather than a prescription. Everything is calculated locally in your browser.
Features
- Estimates daily maintenance calories (TDEE) from weight, height, age, sex, and activity
- Uses the Mifflin-St Jeor formula, a standard, well-studied resting-energy equation
- Adjusts your target for mild or standard weight loss or gain goals
- Supports both metric (kg, cm) and US (lb, ft/in) units with one toggle
- Five activity levels from sedentary to very active, each with a short description
- Shows the estimated weekly weight change your target calories imply
- Copy a plain-text summary of your maintenance and target calories
- Runs entirely in your browser with no stats sent anywhere
How to use the Calorie Calculator
- Choose metric or US units and enter your sex, age, weight, and height
- Pick the activity level that best matches your typical week
- Select your goal: maintain weight, lose, or gain, mild or standard
- Read your maintenance and target calories, and copy the summary if needed
Example
Input
TDEE 2500, lose weight
Output
Target: 2,000 cal/day
Common errors & troubleshooting
- Maintenance calories look too high or too low compared to what you expected. — Double-check the unit toggle — entering pounds as if they were kilograms (or feet/inches as centimeters) skews the result significantly.
- Target calories did not change after switching the goal. — The Calorie Calculator only recomputes once age, weight, and height are all filled in and greater than zero; fill in every field to see the target update.
- The weekly weight-change estimate seems overly precise. — It is a rough estimate based on roughly 3,500 calories per pound of body weight — real-world results vary with water weight, metabolism, and adherence.
- Numbers do not match a different online calorie calculator. — Different calculators use different formulas (Mifflin-St Jeor, Harris-Benedict, Katch-McArdle) and activity multipliers, so small differences between tools are expected.
Frequently asked questions
- How does the Calorie Calculator estimate my daily calorie needs?
- It calculates your resting energy use with the Mifflin-St Jeor formula from your weight, height, age, and sex, then multiplies that by an activity factor to estimate maintenance calories (TDEE), and finally adjusts the total for your selected goal.
- Is the Calorie Calculator's result medical advice?
- No. The Calorie Calculator gives a general estimate from a standard formula, not medical advice. Talk to a doctor or registered dietitian before making significant changes to your diet.
- What is the difference between maintenance and target calories in this calculator?
- Maintenance calories are the estimated amount that keeps your weight roughly stable at your current activity level. Target calories add or subtract an offset from maintenance based on the weight-loss or weight-gain goal you choose.
- How much should I subtract from maintenance calories to lose weight?
- The Calorie Calculator uses a 250 cal/day deficit for a mild loss goal and a 500 cal/day deficit for a standard loss goal, which corresponds to roughly half a pound and one pound of weight loss per week.
- Can I use the Calorie Calculator with US units instead of metric?
- Yes. Toggle to US units to enter weight in pounds and height in feet and inches; the calculator converts everything to metric internally before estimating your calories.
- Does the Calorie Calculator upload my weight, height, or age?
- No. The Calorie Calculator runs entirely in your browser. The stats you enter never leave your device and are not uploaded to ArrayKit.
Related tools
- TDEE Calculator — Estimate total daily energy expenditure from BMR and activity level.
- BMR Calculator — Estimate your basal metabolic rate — the calories your body burns at rest.
- Macro Calculator — Split your daily calories into protein, carbs and fat grams by ratio.
- Protein Calculator — Estimate your daily protein needs from weight and activity level.
- BMI Calculator — Calculate body mass index and see the healthy weight range for your height.
- Calories Burned Calculator — Estimate calories burned by activity using MET values, weight and time.
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