Free Fitness Calculators — BMI, 1 Rep Max & Macro Calculator

Calculate Your Numbers

Pick a calculator below and get your results instantly.

BMI Calculator

Enter your weight and height to calculate your Body Mass Index.

Weight (kg)

Height (cm)

—

Body Mass Index

UnderweightBelow 18.5

Healthy weight18.5 – 24.9

Overweight25 – 29.9

Obese30 and above

BMI is one indicator of health. It doesn't account for muscle mass — athletes often have a higher BMI despite being very lean.

1 Rep Max Calculator

Estimate your one rep max using the Epley formula — without risking a max effort lift.

Weight lifted

Unit

Reps completed

—

Estimated 1 Rep Max

Estimated 1RM—

90% Training Max—

85% Working Weight—

80% Working Weight—

Uses the Epley formula: 1RM = weight × (1 + reps ÷ 30). Best for 1–10 rep ranges.

Macro Calculator

Calculate your daily calorie and macro targets based on your goal and activity level.

Weight (kg)

Goal

Activity level

—

Daily Calories

Protein—

Carbohydrates—

Fat—

Based on estimated BMR using body weight. For personalised targets based on your height, age and full stats, use the Macro Calculator inside the REVIVE app.

All Three Calculators Are Built Into REVIVE

Get the BMI Calculator, 1 Rep Max Calculator and Macro Calculator all inside the REVIVE app — available on iPhone now, free to download.