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Home› Health Calculators› Nutrition› Calorie Needs Calculator

Calorie Needs Calculator
with Maintenance, Cut & Bulk Targets

Estimate daily calorie needs from BMR and activity level, then compare maintenance, moderate cut, aggressive cut, and lean bulk calorie targets.

🔥
Calorie Needs Calculator
⚥
Needed for the BMR formula used in this calculator.
yrs
Required for calorie estimation and context.
Metric inputs
cm
Standing height in centimetres.
kg
Current body weight in kilograms.
%
Optional. Used for Katch-McArdle comparison when available.
Imperial inputs
ft
Feet part of height.
in
Inches part of height.
lb
Current body weight in pounds.
%
Optional. Used for Katch-McArdle comparison when available.
Activity & Goal Context
ACT
Used to turn BMR into estimated maintenance calories.
🎯
Used to highlight the most relevant daily calorie target.
Method note
This calculator uses Mifflin-St Jeor BMR as the main baseline. If body fat percentage is entered, it also shows a Katch-McArdle comparison based on lean body mass.
Recommended Daily Target
—
based on selected goal
BMR
—
Mifflin-St Jeor baseline
Maintenance
—
estimated total daily energy expenditure
Moderate Cut
—
around 15% below maintenance
Aggressive Cut
—
around 25% below maintenance
Lean Bulk
—
around 10% above maintenance
Aggressive Cut
—
Larger deficit, usually harder to sustain.
Moderate Cut
—
More moderate deficit for fat loss.
Maintenance
—
Estimated weight maintenance intake.
Lean Bulk
—
Small surplus for gradual gain.
Input summary
Height used—
Weight used—
Sex—
Age—
Body fat entered—
Energy summary
Activity level—
Goal—
Mifflin BMR—
Katch-McArdle BMR—
Recommended target—
Calorie Target Comparison
Plan Daily Calories Change vs Maintenance General Use
Calorie Calculation Breakdown
Unit system—
Age—
Sex—
Mifflin-St Jeor BMR—
Katch-McArdle BMR—
Maintenance calories—
Moderate cut calories—
Aggressive cut calories—
Lean bulk calories—
Selected target—
This calculator provides general calorie estimates and is not medical advice. Energy needs vary with training volume, body composition, hormones, stress, and measurement error.
✦ Cal, AI Explanation
Cal is reviewing your calorie targets...
💬 Ask Cal about your calorie targets
Cal
Your calorie result is ready. Ask me how maintenance differs from a cut, how the lean bulk target was set, or why BMR and maintenance are not the same.

💡 Calorie Notes

BMR is the baseline estimate of energy used at rest.
Maintenance calories are BMR adjusted by activity level.
Cut targets are below maintenance, while bulk targets are above maintenance.
Katch-McArdle can differ from Mifflin-St Jeor if body fat percentage is entered.
Daily calorie targets are estimates, not exact guarantees.

Related Calculators

BMR Calculator→ Protein Calculator→ Body Fat Percentage Calculator→ BMI Calculator→ Ideal Weight Calculator→

Related Guides

Calorie Needs Explained→ BMR vs Maintenance Calories→ How to Set a Calorie Deficit→

How calorie needs are estimated here

This calculator starts with basal metabolic rate, or BMR. BMR estimates how many calories your body uses at rest. It then multiplies BMR by an activity factor to estimate maintenance calories, also called total daily energy expenditure.

From that maintenance estimate, the calculator builds common planning targets for moderate fat loss, aggressive fat loss, and lean bulking.

Core formulas

Maintenance Calories = BMR × activity multiplier
Moderate Cut = maintenance × 0.85
Aggressive Cut = maintenance × 0.75
Lean Bulk = maintenance × 1.10
Mifflin-St Jeor is used as the main BMR estimate. Katch-McArdle is shown only when body fat percentage is available.

BMR vs maintenance calories

BMR is not the same as daily calorie needs. BMR estimates resting energy use only. Maintenance calories include movement, exercise, and general daily activity, which is why the maintenance number is higher.

This difference is important because most people should plan cuts, maintenance, and bulks from maintenance calories, not from BMR alone.

Measure Meaning Used For
BMRResting baseline energy estimateStarting point
MaintenanceBMR adjusted for activityWeight maintenance planning
Cut targetCalories below maintenanceFat loss planning
Lean bulk targetCalories above maintenanceGradual gain planning

Why Katch-McArdle is optional

Katch-McArdle uses lean body mass, so it requires body fat percentage. When body fat is entered, the calculator can compare a lean-mass-based BMR with the standard Mifflin-St Jeor result. If body fat is not entered, the main estimate remains Mifflin-St Jeor.

This is useful because the two methods may differ when body composition differs significantly from average assumptions.

Frequently Asked Questions

What is the difference between BMR and maintenance calories?+
BMR is the estimated energy your body uses at rest. Maintenance calories are your estimated daily calories after activity is added on top of BMR.
Why does the calculator show multiple targets?+
Because the best calorie target depends on the goal. Maintenance, fat loss, and lean bulking all require different energy levels.
What is a moderate cut?+
In this calculator, a moderate cut is about 15% below maintenance calories. It is a structured middle ground between maintenance and a more aggressive deficit.
Why is Katch-McArdle optional?+
Because it needs lean body mass, which requires body fat percentage. Without body fat input, the calculator cannot produce the Katch-McArdle estimate.
Are these calorie numbers exact?+
No. They are structured estimates. Real calorie needs vary with training load, body composition, movement, recovery, and measurement error.