Calorie and Macro Calculator: Precisely Determine Basal Metabolic Rate and Daily Needs

To determine your personal calorie and macro requirements, you combine individual measurements with an activity factor.

Mifflin‑St Jeor vs. Katch‑McArdle – which equation fits you?

Basal metabolic rate (BMR) is the foundation of any nutrition plan. The Mifflin‑St Jeor and Katch‑McArdle equations are among the most frequently cited methods in expert circles; the choice depends on the available input data. Mifflin‑St Jeor requires gender, age, height and weight – data most people have on hand. Katch‑McArdle works with lean body mass, making it gender‑neutral and especially useful when you already know your body‑fat percentage.

Example: A 70 kg male, 180 cm tall, 25 years old yields a BMR of roughly 1 660 kcal with Mifflin‑St Jeor. If his lean mass is 60 kg, Katch‑McArdle gives a BMR of about 1 560 kcal.

Choosing a PAL factor and calculating daily energy needs

Physical Activity Level (PAL) is a multiplier that converts BMR into total daily energy expenditure (TDEE). Examples of PAL values are typically distinguished from “low” to “very high” activity. Select the factor that best matches your average movement – for instance, an appropriate value for a schedule of three‑to‑four 45‑minute training sessions per week.

Example: BMR = 1 660 kcal, PAL = 1.6 → TDEE ≈ 2 656 kcal.

Protein recommendations for strength and endurance athletes

For recovery and muscle growth, there are various recommendations for protein intake. This range supports both recovery and muscle growth across strength and endurance disciplines and can be fine‑tuned to personal goals.

Putting a calorie deficit or surplus into practice

Once you know your TDEE, you decide whether to lose weight, maintain it, or build muscle. A deficit occurs when daily intake falls below TDEE; a surplus when it exceeds TDEE. Many programs suggest a moderate deficit as a starting point, which can lead to weight loss, assuming the energy balance remains stable. For muscle gain, a surplus is commonly recommended to provide sufficient energy for anabolic processes. The exact percentage is then refined through weekly weight monitoring.

Using online calculators to get BMR and TDEE instantly

A few clicks save time and eliminate manual errors. Three reputable tools are available:

Omni‑Calculator BMR Calculator (implements Mifflin‑St Jeor) – ideal when you have only weight, height, age and gender.
BusinessBike Calorie Calculator (uses Katch‑McArdle) – perfect if you know your lean mass.
MarathonFitness BMR Calculator (offers Harris‑Benedict as an alternative) – useful for side‑by‑side formula comparisons.

Enter your data, select the appropriate PAL factor, and receive both BMR and TDEE instantly. Most of these calculators also provide a quick view of how to adjust your intake for a desired deficit or surplus, without relying on unsupported percentage claims.

Try it yourself: Calorie & Macro Calculator