Fitness Age Calculator

It is common that some people look older or younger than their biological age, and while you already know your chronological (birthday) age, you might still be curious to know your fitness age, which depends on your actual age and lifestyle.

We have prepared a Fitness Age Calculator that estimates your fitness age based on factors such as age, gender, fitness level, and resting heart rate.

Remember that fitness age is not the same as your birthday age. It shows how efficient and healthy your heart, lungs, immune system, and overall aerobic performance are compared to people in your age group.

What Is Fitness Age?

Fitness age is a metric that estimates how your aerobic fitness compares to the average person of your chronological age.

For instance, if you are 25 years old but your cardiovascular fitness matches an average 30-year-old, it means your fitness age is 30.

Fitness age depends on key factors such as:

• VO₂max (considered the main factor)
• Resting heart rate
• Age
• Gender
• Activity level
• Aerobic conditioning

How Fitness Age Is Calculated?

The logic behind fitness age is simple: it compares your VO₂max with the typical VO₂max values from an age- and gender-based reference curve.

Based on your fitness level and resting heart rate, the calculator estimates your VO₂max if you don’t already know it. In the coming example section, we demonstrate how exactly the VO₂max can be calculated manually.

Here is the simple logic:

• Higher VO₂max → lower fitness age (younger body)
• Lower VO₂max → higher fitness age (older body)

What VO₂max reference does the calculator use?

Here are the VO₂max values that the calculator is using for fitness age:

• Males age 20 ≈ 50 mL/kg/min
• Females age 20 ≈ 47.5 mL/kg/min

Then the VO₂max declines ~0.5 per year after age 20. For ages 20 or below, the same baseline values are used 50 mL/kg/min for males and 47.5 mL/kg/min for females.

For instance, a male aged 40 has a reference VO₂max of:

50 – (20×0.5) = 40 mL/kg/min

Based on gender, we start from a baseline VO₂max at age 20, to aproximate your fitness age:

Fitness age ≈ 20 years + (baseline VO₂max − your VO₂max) / 0.5

Remember that higher VO₂max pulls the result closer to 20 year age, and lower VO₂max pushes it toward older ages.

How to Estimate VO₂max — 2 Methods

The good news is that you don’t need any lab test to estimate VO₂max. You can accurately estimate it using the most common and simple methods, which we will describe below.

Method 1 — Using Resting Heart Rate (RHR)

We estimate VO₂max using resting heart rate because people with stronger cardiovascular fitness have lower resting heart rates.

Here is the formula:

VO2max = 15.3 × (HRmax / RHR)

Where:

• HRmax (maximum heart rate) can be estimated using the Tanaka formula:
  • HRmax = 208 – (0.7 × age)
• RHR = resting heart rate (beats per minute, measured when you wake up)

Example:

Assume your age is 30 year and resting heart rate (RHR) is 60 bpm.

• Age: 30
• RHR: 60 bpm

Step 1: HRmax (Tanaka)

• HRmax ≈ 208 − 0.7 × age
• 208 – (0.7 × 30)
• 208 – 21
• HRmax ≈ 187 bpm

Step 2: VO2max (Uth method)

• VO2max ≈ 15.3 × (HRmax ÷ RHR)
• 15.3 × (187 / 60)
• 15.3 × 3.11
• VO2max ≈ 47.6 mL/kg/min

So we estimated your VO₂max is ≈ 47.6.

Method 2 — Field Test (Cooper 12-Minute Run Test)

A field test is a popular and widely used real-world method that accurately estimate VO₂max. This method is used by coaches, sports communites and popular apps.

There are many field test but in this guide we will explain the Cooper 12-minute run test which is widely used.

Cooper 12-Minute Run Test:

In this test, run or walk as far as possible in 12 minutes to determine your VO₂max.

Here is the formula:

VO₂max = (Distance in meters – 504.9) ÷ 44.73

Example:

Suppose you cover distance 2,400 meters in 12 minutes.

Let's compute:

• VO₂max = (2400 – 504.9) ÷ 44.73
• = 1,895.1 ÷ 44.73
• VO₂max = 42.3 mL/kg/min

How to Calculate Fitness Age — Example

We are going to explain steps involved to estimate your fitness age manually. To calculate fitness age, we need your VO₂max that we had already describe you 2 easiest method you can use to estimate your VO₂max.

Determine your resting heart rate (RHR) e.g. 52, your sex e.g. female, and lastly your age e.g 40 year.

How to Boost Fitness Age

Fitness age can be improved at any age by following workouts and exercises that strengthen your main organs such as the heart, lungs, and overall blood flow. These improvements directly lower your fitness age compared to your chronological age. We are going to explain some key factors that help you boost your fitness age:

• Cardio workout: There are many cardio exercises such as running, swimming, rowing, and even incorporating HIIT, which strengthen your heart and lungs.
• Strength training: Train and challenge your muscles to build strength and improve oxygenation
• Consistency over intensity: If you train intensely for a few days but then skip many days, the benefits decrease. Prioritize consistency over intensity.
• Clean diet: It matters a lot what you feed your body. Eat healthy foods so your body can absorb nutrients for recovery, muscle building, and overall fitness.
• Keep checking your RHR: While you are training with consistency, monitor your resting heart rate because a lower RHR usually means your fitness age is improving.