GSCalculate

Calorie Calculator

Estimate daily calorie needs (BMR and TDEE) from age, sex, height, weight, and activity. Free Mifflin-St Jeor planning with lose / maintain / gain targets.

Reviewed / updated August 4, 2026

Your inputs

Mifflin-St Jeor uses sex-specific constants

years
lb

Result

Maintenance calories (TDEE)

2,197 kcal

BMR ≈ 1,417 kcal/day

BMR (Mifflin-St Jeor)
1417 kcal
Lose (~500 deficit)
1697 kcal
Maintain
2197 kcal
Gain (~500 surplus)
2697 kcal

Estimated maintenance is about 2197 kcal/day using Mifflin-St Jeor × your activity factor. Treat this as a starting point, not a prescription.

Suggested next steps

  • Check your BMI on the BMI Calculator for a height/weight screening companion.
  • A common planning deficit/surplus is ~500 kcal/day (~1 lb/week) — adjust slowly and monitor energy.
  • Athletes, pregnancy, and medical conditions need individualized guidance from a clinician or RD.

How the calorie calculation works

  1. Convert height and weight to metric if needed.
  2. Compute BMR with Mifflin-St Jeor (sex-specific).
  3. Multiply by an activity factor (sedentary 1.2 through very active 1.9) for TDEE.
  4. Show rough lose / maintain / gain targets (± ~500 kcal).

Results update as you change inputs. Rule-based tips describe your activity band and point you to the BMI Calculator for a height/weight screening companion.

Worked example

Woman, age 30, height 5′6″, weight 150 lb, moderate activity:

  1. Convert ≈ 68 kg and 168 cm
  2. BMR ≈ 10×68 + 6.25×168 − 5×30 − 161 ≈ 1,400 kcal
  3. TDEE ≈ 1,400 × 1.55 ≈ 2,170 kcal maintain
  4. Lose/gain bands ≈ 1,670 / 2,670 kcal (illustrative ±500)

Methodology and notes

Equations run in your browser. Activity multipliers are standard Harris–Benedict–style lifestyle factors applied to Mifflin-St Jeor. This is not medical advice; athletes, illness, and medications can change needs substantially.

Frequently asked questions

It estimates basal metabolic rate (BMR) with the Mifflin-St Jeor equation, then multiplies by an activity factor to estimate total daily energy expenditure (TDEE). Lose/gain suggestions use about a 500 kcal/day adjustment from maintenance.

Related tools

Related calculators — live tools and upcoming pages for internal linking.