Calorie Calculator
Find your daily calorie needs (TDEE) with personalized deficit and surplus targets for weight loss, maintenance and muscle gain — using Mifflin-St Jeor and activity multipliers.
Your Details
Activity multiplier: ×1.55
Enter your details to see your personalized calorie targets.
About Calorie Calculator
The Calorie Calculator estimates your Total Daily Energy Expenditure (TDEE) — how many calories you burn in a typical day including activity, not just at rest. It starts from your BMR (Mifflin-St Jeor) and multiplies it by an activity factor you select, then shows maintenance, mild deficit/surplus and aggressive deficit/surplus targets.
Use it to set a realistic starting calorie target for weight loss, maintenance or muscle gain, then adjust based on real-world results after a couple of weeks. The selectable activity factor accounts broadly for daily movement and exercise, but it is not a measurement from a wearable or metabolic lab.
Body-weight trends over several weeks are more informative than a single day of intake. Hydration, sodium, digestion and menstrual-cycle changes can move scale weight temporarily even when the underlying energy balance is unchanged.
How Calorie Calculator works in practice
- 1Enter your age, biological sex, height and weight.
- 2Select your activity level, from sedentary (desk job, little exercise) to very active (physical job or intense daily training).
- 3Read your maintenance calories, plus suggested targets for mild and aggressive weight loss or gain.
- 4Revisit the calculator every few weeks as your weight changes — TDEE shifts as you gain or lose.
Jobs this tool is built for
- Choose an initial maintenance target before beginning food-intake tracking.
- Plan a moderate calorie deficit for gradual weight loss rather than guessing.
- Estimate a small surplus to support resistance training and muscle gain.
- Recalculate needs after a meaningful weight or activity-level change.
What you can do here
- BMR-based TDEE using the Mifflin-St Jeor equation
- Five standard activity multipliers
- Maintenance, deficit and surplus targets in one view
- Metric and imperial input
Limits and honest caveats
- This is an estimate, not a lab measurement — actual burn varies by 10–20% between individuals with identical stats.
- Very aggressive deficits (more than ~20–25% below maintenance) risk muscle loss and are generally not recommended without medical supervision.
- This tool does not account for pregnancy, breastfeeding, or diagnosed metabolic conditions — consult a doctor or dietitian for those situations.
Common questions about Calorie Calculator
How big a deficit do I need to lose weight?
A deficit of roughly 500 calories/day is a common target for losing about 0.5 kg (1 lb) per week, since one pound of fat is roughly 3,500 calories.
What activity level should I pick if I'm not sure?
Most people overestimate their activity level. If you sit most of the day and exercise 0–2 times a week, "sedentary" or "lightly active" is usually more accurate than "moderately active."
Why does my target change as I lose weight?
TDEE is based on your current body weight, so it drops as you lose weight — recalculating periodically keeps the target accurate.
How do I know whether the estimate is right for me?
Track consistent intake and average body weight for two to four weeks. If the trend differs from your goal, adjust gradually rather than treating the estimate as exact.
This page was written by the ToolSink team to explain how Calorie Calculator works on this site — it is not syndicated, scraped, or spun from another publisher. How we write tool guides · Site updates · About ToolSink.
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