Health & Fitness Calculators
Calorie Calculator
Estimate BMR, TDEE, maintenance calories, and simple deficit or surplus planning targets.
US units are selected by default. Switch to metric if needed.
Calculation assumptions
- *BMR is estimated with the Mifflin-St Jeor equation.
- *Maintenance calories are estimated by multiplying BMR by the selected activity factor.
- *The 500-calorie deficit and surplus rows are simple planning examples, not personalized diet advice.
- *Calorie needs vary by age, sex, body size, activity, health status, pregnancy, medications, eating-disorder history, goals, and tracking accuracy.
Enter your values and press Calculate.
Results and breakdowns will appear here after a valid calculation.
What is a calorie calculator?
A calorie calculator estimates daily energy needs from age, sex, height, weight, and activity level. It is useful for general planning because it separates resting needs from estimated daily activity.
Use the result as a starting estimate, then compare it with real-world tracking, appetite, energy, training, and guidance from a qualified professional when health concerns are involved.
BMR vs TDEE vs maintenance calories
BMR is the estimated energy your body uses at rest. TDEE adds an activity multiplier to estimate total daily calories. Maintenance calories are the estimated intake that would roughly match that daily energy use.
This calculator uses the Mifflin-St Jeor BMR equation, then applies the selected activity factor: TDEE = BMR x activity multiplier.
Calorie deficit and surplus planning
A calorie deficit means eating below estimated maintenance. A calorie surplus means eating above estimated maintenance. The -500 and +500 rows are simple examples for planning, not exact predictions.
The common 3,500-calorie-per-pound shortcut can help with rough planning, but real body-weight changes can differ because of water weight, adherence, metabolic adaptation, activity changes, digestion, and measurement error.
Worked example
Maintenance example: a 25-year-old male at 180 lb and 5 ft 10 in has an estimated BMR around 1,808 calories/day. With moderate activity at 1.55, estimated maintenance is about 2,802 calories/day.
Planning example: a small deficit could start below maintenance, while a surplus could start above maintenance. Pair this page with the Macro Calculator if you want to split calories into protein, carbs, and fat.
Why results can differ from real-world changes
Formula results are estimates. Actual changes can vary because food labels, portion sizes, activity trackers, sleep, stress, medical factors, menstrual cycle changes, and day-to-day water weight can all affect the scale or energy needs.
Safety notes and common mistakes
Calorie estimates are for general education and planning only. They are not medical advice, diagnosis, treatment, or a guaranteed weight-change plan.
- Do not overstate your activity level.
- Do not treat the 500-calorie adjustment as right, safe, or realistic for every person.
- Do not use extreme deficits to chase faster results.
- Do not use this to manage a medical condition without professional guidance.
- Pregnant people, people under 18, older adults, athletes, people with eating-disorder history, and anyone with medical concerns should use professional guidance.
For broader context, compare this with the BMI Calculator, Body Fat Calculator, Ideal Weight Calculator, Heart Rate Zones Calculator, and Health & Fitness Calculators.
Transparency note
Accuracy and limitations
Calzivo tools are built for practical estimates, conversions, and checks. Some tools use standard formulas or simplified assumptions, and results can be affected by input accuracy, rounding, units, local rules, or changing official requirements.
Health and fitness results are estimates, not medical advice. Formulas simplify real bodies and cycles, so important health decisions should be checked with a qualified clinician.
How to Use This Tool
Use these steps to enter the right inputs and interpret the result correctly.
Choose US or Metric units, then enter your age, weight, and height.
Choose your typical activity level.
Review estimated BMR, maintenance calories, and simple deficit or surplus planning examples.
Related Tools
Other helpful tools in the Health & Fitness Calculators category.
BMI Calculator
Calculate body mass index from height and weight, see the adult category, and understand screening limitations.
Macro Calculator
Estimate daily protein, carbs, fat, calories, and macro split targets from body stats, goals, and activity.
Body Fat Calculator
Estimate body fat percentage with Navy circumference or BMI-based methods, reference ranges, and neutral context.
Ideal Weight Calculator
Compare common ideal-weight formulas with a healthy BMI range and clear estimate limitations.
Heart Rate Zones Calculator
Calculate Zone 2, max-HR, and Karvonen heart-rate-reserve zones for general fitness planning.
Chipotle Calorie Calculator
Build a Chipotle meal by ingredient and estimate calories, protein, carbs, fat, and nutrition totals.
BMR Calculator
Estimate basal metabolic rate with age, sex, height, and weight inputs for general calorie planning context.
Related Guides
Background reading and explanations related to Calorie Calculator.
Frequently Asked Questions
Common questions about Calorie Calculator and how to read the result.
How accurate is this?
It is an estimate based on formula inputs and activity selection. Individual metabolism, body composition, tracking accuracy, and health status can vary.
What is TDEE?
TDEE means Total Daily Energy Expenditure. It estimates daily calories burned after activity is added to BMR.
Is BMR the same as maintenance calories?
No. BMR estimates calories at rest, while maintenance calories estimate daily needs after activity.
Does this create a meal plan?
No. It only estimates calorie targets. Food choices, nutrients, medical needs, and meal planning are not included.
Can I use this as a calorie deficit calculator?
Yes, as a general planning estimate. Use maintenance calories as the baseline, then compare the deficit row with your needs and avoid extreme targets.
Is the 3,500-calorie rule exact?
No. It is a rough planning shortcut. Real weight changes can differ because of water weight, activity, body composition, adherence, and metabolic changes.
Can calorie needs change over time?
Yes. Weight, activity, health status, age, and body composition can change calorie needs.
Who should get professional guidance?
People who are pregnant, under 18, older adults, athletes, or anyone with a medical condition should use professional guidance.