Calorie Calculator: BMR, TDEE & Daily Needs Explained
Knowing roughly how many calories you burn each day is the starting point for most weight goals. A free calorie calculator estimates BMR and TDEE, then suggests daily targets to lose, maintain, or gain — without a signup.
This guide explains the Mifflin-St Jeor equations, activity multipliers, goal calorie math, and the limits of any online estimate. It is educational, not medical advice.
Estimate BMR, TDEE & goal calories
Free calorie calculator — Mifflin-St Jeor, metric or imperial, no signup.
BMR vs TDEE
- BMR — energy your body needs at complete rest (organs, brain, basic metabolism).
- TDEE — BMR scaled by how active you are; often used as maintenance calories.
Mifflin-St Jeor Formula
Widely used for adults. Convert imperial inputs to kilograms and centimeters first (the ToolMars tool does this for you):
Women: BMR = 10×kg + 6.25×cm − 5×age − 161
TDEE = BMR × activity multiplier
Example: 30-year-old man, 70 kg, 170 cm, moderate activity
BMR = 10×70 + 6.25×170 − 5×30 + 5 = 700 + 1,062.5 − 150 + 5 = 1,617.5 kcal. With moderate activity (×1.55), TDEE ≈ 2,507 kcal/day. Lose target ≈ 2,007; gain ≈ 2,807.
Activity Multipliers
| Level | Multiplier | Typical lifestyle |
|---|---|---|
| Sedentary | 1.2 | Desk job, little exercise |
| Light | 1.375 | Exercise 1–3 days/week |
| Moderate | 1.55 | Exercise 3–5 days/week |
| Active | 1.725 | Exercise 6–7 days/week |
| Very active | 1.9 | Hard training or physical job |
Estimate BMR, TDEE & goal calories
Free calorie calculator — Mifflin-St Jeor, metric or imperial, no signup.
Goal Calories
- Lose: about TDEE − 500 kcal/day (roughly ~0.5 kg / 1 lb per week).
- Maintain: eat near TDEE.
- Gain: about TDEE + 300 kcal/day as a gentle surplus in this tool.
Track weight and energy for a few weeks and adjust. Pair calorie targets with protein, sleep, and training — and check BMI only as one screening number among many.
Not medical advice. Formulas misestimate for some bodies (high muscle, illness, pregnancy, certain medications). Get personalized guidance from a qualified professional.
Related Tools on ToolMars
- Calorie Calculator — BMR, TDEE, goal calories
- BMI Calculator — height/weight screening
- Steps to Miles Calculator — walking distance from steps
- A1C Calculator — A1C to estimated average glucose
Estimate BMR, TDEE & goal calories
Free calorie calculator — Mifflin-St Jeor, metric or imperial, no signup.
Frequently Asked Questions
What is BMR vs TDEE?
BMR is rest metabolism; TDEE is daily burn including activity.
How many calories to lose weight?
Often start near TDEE − 500, then adjust with real results.
Is Mifflin-St Jeor accurate?
One of the better adult formulas — still an estimate, not a lab test.
Is the calorie calculator free?
Yes on ToolMars — no signup.