Recommended Tool Path
Use the guide to choose the right method, then open the matching tool when you are ready to calculate, reflect, or plan a next step.
The Short Version
The Mifflin-St Jeor equation is not the final daily calorie goal. It estimates BMR first. TDEE adds an activity multiplier. A calorie goal then adjusts that maintenance estimate for your current objective.
Mifflin-St Jeor Is The Formula Step
The Mifflin-St Jeor equation uses weight, height, age, and sex-specific constants to estimate resting energy expenditure.
Women: 10W + 6.25H - 5A - 161
W is weight in kilograms, H is height in centimeters, and A is age in years. The equation returns a BMR estimate, not a full-day maintenance number.
BMR vs TDEE vs Maintenance Calories
| Number | What it answers | Best tool |
|---|---|---|
| BMR | How many calories might the body use at rest? | BMR Calculator |
| TDEE | How many calories might maintain weight after activity? | TDEE Calculator |
| Maintenance calories | What daily intake should I test for weight maintenance? | TDEE first, then calibration |
| Calorie goal | What target should I use for deficit, maintenance, or surplus? | Daily Calorie Goal Calculator |
Activity Multipliers Are The Biggest Assumption
The activity multiplier can move the estimate by hundreds of calories. A formula can be correct while the activity label is still too high or too low for a real week.
When uncertain, choose a conservative activity level, hold intake steady for two to four weeks, and compare average body-weight trend before changing the formula.
A Practical Sequence
- Use the BMR calculator if you want the formula-only resting estimate.
- Use the TDEE calculator if you want estimated maintenance calories.
- Use the calorie goal calculator only after maintenance is chosen.
- Use maintenance calibration after you have real intake and weight trend data.
When To Avoid Over-Precision
Pregnancy, breastfeeding, growth, illness recovery, eating-disorder history, medical nutrition needs, and aggressive weight-change goals require individualized professional guidance. These calculators are useful starting estimates, not prescriptions.
Frequently Asked Questions
Is Mifflin-St Jeor the same as TDEE?
No. Mifflin-St Jeor estimates BMR. TDEE starts with BMR and adds an activity multiplier.
Is TDEE the same as maintenance calories?
TDEE is an estimated maintenance calorie number. Real maintenance can differ, so calibration from intake and weight trend is useful.
Should I calculate BMR or TDEE first?
Use BMR first if you want the formula baseline. Use TDEE first if your practical question is maintenance calories.
Why do calorie calculators give different results?
They may use different equations, activity assumptions, rounding, goal adjustments, or calibration logic.
Sources And Further Reading
- A New Predictive Equation for Resting Energy ExpenditureThe American Journal of Clinical Nutrition / PubMed
- Body Weight PlannerNational Institute of Diabetes and Digestive and Kidney Diseases