MIFFLIN - ST JEOR
Formula by sex, age, height, and weight
For men: BMR = 10 x W + 6.25 x H - 5 x A + 5
For women: BMR = 10 x W + 6.25 x H - 5 x A - 161
Works well when you only have the basics.
Calorie calculator and US food database
Calculate daily calories and macros, then browse US foods, supermarket products, brands, and serving sizes.
- Catalog
- US foods, supermarket products, brands, and serving sizes
- Calculator
- lb, ft/in, and weekly pace in lb
- Next step
- compare foods, brands, categories, and portions for your target
FAQ
Quick answers before your first calculation in compact expandable cards.
Start
Is this calculation enough to get started?
Start
Is this calculation enough to get started?
Yes. To start, it is enough to get daily calories and macros, then compare them with real foods and watch the trend for 10–14 days.
Body composition
Do I need to fill in the body composition fields?
Body composition
Do I need to fill in the body composition fields?
No. They only refine the model. The basic calculation works without them.
Next step
What should I do after I get the result?
Next step
What should I do after I get the result?
Open the catalog or the portion calculator and map the target to real foods and portion weights.
Goal
Can I use this result to lose weight?
Goal
Can I use this result to lose weight?
Yes, if you choose a weight-loss goal and then track how your weight and wellbeing respond, not only the theory.
Methodology
Where can I see formulas and calculation details?
Methodology
Where can I see formulas and calculation details?
If you need formulas and detailed explanations, open the methodology page.
US foods and brands
Open the United States catalog to compare calories, macros, product pages, and portion calculations.
Quick calculation outline
How to read the result
This is not a quick cheat sheet — it is the logic behind the calculation: where each number comes from, which formulas are used, and what the real accuracy boundaries are.
- BMR
- basal energy expenditure at rest. This is the minimum energy for breathing, heart work, body temperature, and other background processes.
- Activity
- a factor that turns BMR into maintenance calories — an estimate for your current weight in your usual routine.
- Goal
- an adjustment to maintenance. For weight loss calories go down, for gain go up, and for maintenance they stay without an extra shift.
- Macros
- computed from the target: protein and fat are based on weight, while carbs take the remaining calories.
Use the switch above the form to choose MIFFLIN - ST JEOR or KATCH - MCARDLE if you know body fat percentage or have measurements.
What the calculation shows
The result has two main numbers. The first is maintenance calories: an estimate for your current weight. The second is the daily target: the same base, but adjusted for loss, gain, or maintenance. If you choose to maintain weight, there is no separate adjustment.
If you enter a target weight and pace, the calculator also shows an estimated time to reach the goal. It is not a promise of an exact date — just a working estimate. KATCH - MCARDLE requires body fat percentage or measurements to estimate it.
How BMR is calculated
You can choose the formula manually. MIFFLIN - ST JEOR uses sex, age, height, and weight. KATCH - MCARDLE is based on lean body mass and therefore requires body fat percentage or measurements to estimate it.
KATCH - MCARDLE
Formula by lean body mass
Lean mass = W x (1 - F / 100)
BMR = 370 + 21.6 x lean mass
Requires body fat percentage or measurements to estimate it.
- W
- weight in kg
- H
- height in cm
- A
- age in full years
- F
- body fat percentage
What changes your daily total
After BMR, the calculator multiplies it by an activity factor. The site offers five levels: from sedentary lifestyle to very high load. This gives maintenance calories — an estimate for your current weight given your typical day.
For loss and gain, pace is applied. The calculator converts it into a deficit or surplus using a simple rule: about 7,700 kcal per 1 kg of body mass. For loss this adjustment is subtracted, for gain it is added. Target weight is not used in the calorie formula itself, but to estimate time to goal.
Sedentary lifestyle
x1.2
Light activity 1–3 times per week
x1.375
Moderate activity 3–5 times per week
x1.55
High activity 6–7 times per week
x1.725
Very high training load or physical job
x1.9
How protein, fat, and carbs are calculated
Protein and fat are set as grams per kilogram of body weight. Carbs take the remaining calories. So the macro split is not a universal plan — it is a direct continuation of your calculation based on weight, activity, and goal.
Fiber is calculated separately: the estimate is based on a simple guideline of about 14 g per 1,000 kcal.
Maintain
- Protein
- 1.6 g/kg
- Fat
- 0.9 g/kg
- Carbs
- remaining calories
Lose
- Protein
- 1.8 g/kg
- Fat
- 0.8 g/kg
- Carbs
- remaining calories
Gain
- Protein
- 2.0 g/kg
- Fat
- 1.0 g/kg
- Carbs
- remaining calories