Calorie Calculator
Estimate your basal metabolic rate (BMR) and daily energy expenditure (TDEE) using Mifflin-St Jeor plus standard activity multipliers. Use outputs as a planning baseline for maintenance, deficit, or surplus strategies, then refine with real trend data over time.
Medical Disclaimer
This calculator is for educational nutrition planning only. It is not a diagnosis tool and does not replace medical advice, especially in pregnancy, chronic disease, or therapeutic nutrition contexts.
Calculate Daily Calories
Your Results
TDEE by Activity Level
Adjustment Checklist and Planning Notes
How to Adjust by Goal
- Weight loss: start 300 to 500 kcal below maintenance.
- Maintenance: use an activity level you can sustain weekly.
- Muscle gain: start 150 to 300 kcal above maintenance.
- Review trend after 2 to 3 weeks before changing targets.
Tracking Quality Checklist
- Track body weight at least 3 mornings per week.
- Keep protein and total calories consistent day to day.
- Use the same activity assumptions when comparing periods.
- Do not react to one-day fluctuations.
Medical Note
BMR and TDEE are model estimates. Pregnancy, endocrine disease, active illness, medication changes, and clinical nutrition therapy may require individualized supervision beyond calculator output.
Editorial & Review Information
Reviewed on: 2026-02-24
Published on: 2025-01-05
Author: LumoCalculator Editorial Team
Editorial review: Formula definitions, activity-multiplier usage, and source-link validity were reviewed against primary equation and major public-health references.
Purpose and scope: Provides baseline calorie estimates for adult planning and trend monitoring. Not intended to prescribe treatment, medications, or disease-specific clinical nutrition protocols.
Use Scenarios
Scenario 1: Maintenance setup
Pick an activity band that matches your repeatable routine and set a starting maintenance target. Track average weight trend before deciding any adjustment.
Scenario 2: Fat-loss planning
Start with a moderate deficit from maintenance and monitor performance, hunger, and weekly trend rate instead of chasing aggressive short-term drops.
Scenario 3: Lean-gain control
Use a small surplus for strength-focused training blocks and adjust intake if weight gain is too fast or if performance is flat despite adequate recovery.
Formula Explanation
Mifflin-St Jeor Baseline
BMR estimates resting energy requirement. It is a model, not a direct metabolic lab reading. TDEE applies activity multipliers to convert resting energy into practical daily intake ranges.
The activity multiplier is often the highest-error input, not the equation itself. Selecting an unrealistically high multiplier can overestimate maintenance by several hundred calories, which then makes a deficit plan fail despite accurate food logging.
For practical coaching use, start with a conservative multiplier, observe 2 to 3 weeks of trend, then calibrate. This approach typically performs better than searching for one perfect starting number.
How to Choose Activity Level Correctly
Use your typical week, not your best week
If training frequency fluctuates, choose based on the most repeatable pattern. Overestimating activity is one of the most common causes of stalled progress.
Separate exercise from total movement
Structured workouts are only one part of energy expenditure. Daily steps, job activity, and non-exercise movement can shift maintenance needs materially.
Re-evaluate after routine changes
If work pattern, training volume, or sleep quality changes, maintenance may shift. Recalculate and validate with trend data instead of assuming old targets still fit.
Treat the multiplier as a starting guess
The model gives a planning baseline, then real-world data should override it. This sequence reduces overcorrection and improves long-term adherence.
Interpreting Results Safely
Calorie estimates are useful for planning, not absolute truth. Two people with similar body size can have different real maintenance levels due to physiology, medication, sleep quality, and movement behavior outside formal exercise.
For fat loss, rate of change matters more than one week of noisy scale data. For lean gain, strength progression and body-composition direction should be reviewed together. In both cases, small consistent adjustments outperform frequent large changes.
If your result conflicts with medical advice, clinician guidance should be prioritized. This tool is designed to improve planning conversations, not replace professional evaluation.
Example Cases
Case 1: Desk worker with moderate training
Input: male, 34 years, 80 kg, 178 cm. BMR is approximately 1,760 kcal/day. Moderate-activity TDEE is around 2,730 kcal/day. Practical use: start maintenance near this value and watch 2-week trend.
Case 2: Fat-loss setup with sustainable deficit
Input: female, 29 years, 70 kg, 165 cm. Moderate-activity TDEE may sit around 2,100 kcal/day. A first-pass loss target near 1,700 to 1,800 kcal/day can balance adherence and performance.
Case 3: Lean gain with controlled surplus
Input: male, 26 years, 72 kg, 176 cm, high training frequency. If maintenance is near 2,700 kcal/day, a surplus to about 2,850 to 3,000 kcal/day is a common controlled starting range.
Common Mistakes and Fixes
Mistake 1: Picking activity too high
Fix: choose the level you can sustain most weeks, then calibrate from trend rather than ambition.
Mistake 2: Overreacting to daily scale noise
Fix: use weekly averages and compare blocks of 2 to 3 weeks before changing targets.
Mistake 3: Large rapid calorie cuts
Fix: start with moderate deficit and preserve training quality, protein intake, and sleep quality.
Mistake 4: Ignoring adherence constraints
Fix: build intake targets around actual schedule, food access, and social constraints so the plan remains repeatable.
8-Week Calibration Framework
Weeks 1-2: Establish baseline behavior
Use one intake target and one activity assumption. Log body weight consistently and avoid frequent target changes while you establish a clean baseline trend.
Weeks 3-5: Evaluate trend direction
If trend does not match goal, adjust by about 100 to 200 kcal/day. Keep protein and training quality stable so adjustments are interpretable.
Weeks 6-8: Confirm and lock working range
Once trend and adherence stabilize, keep the same framework. Recalculate only when body mass, activity pattern, or goals materially change.
Boundary Conditions
- This page is calibrated for adult planning context and uses standardized multipliers.
- Not suitable for pediatric growth planning without age-specific clinical standards.
- Not intended for pregnancy, lactation, eating-disorder treatment, or critical illness.
- Does not account for medication-specific energy-expenditure effects.
- Not an emergency tool or diagnostic tool for endocrine disease.
- When medical guidance differs from calculator output, medical guidance should prevail.
Sources & References
- Mifflin MD, et al. (1990) - New predictive equation for resting energy expenditure - Primary equation source used for BMR estimation.
- NIH NIDDK - Body Weight Planner - Public planning context for calorie balance and weight trend management.
- CDC - Adult BMI calculator and interpretation context - Public-health context for anthropometric tracking alongside calorie planning.
- MedlinePlus - Obesity - Consumer medical context for weight-management risk factors and support needs.