Use this calculator to estimate your Maximum Heart Rate and determine your specific heart rate zones used in Orangetheory Fitness (OTF) classes to earn Splat Points.
Estimated Maximum Heart Rate
0 BPM
Based on the Tanaka Formula (208 – 0.7 × Age)
Zone
Intensity (%)
Heart Rate Range (BPM)
Effect
Note: Orangetheory adjusts your specific Max HR automatically after you complete 20 classes based on your actual performance data. This calculator provides the baseline estimation for new members.
function calculateOTFZones() {
var ageInput = document.getElementById("otfAge");
var age = parseFloat(ageInput.value);
if (isNaN(age) || age 110) {
alert("Please enter a valid age between 10 and 110.");
return;
}
// Calculation Logic
// Orangetheory has shifted towards more accurate formulas like Tanaka over the traditional Fox (220-age).
// Formula: 208 – (0.7 * Age)
var maxHeartRate = 208 – (0.7 * age);
maxHeartRate = Math.round(maxHeartRate);
// Display Max HR
document.getElementById("maxHrResult").innerHTML = maxHeartRate + " BPM";
// Calculate Zones
// Zone 1 (Gray): 50-60%
// Zone 2 (Blue): 61-70%
// Zone 3 (Green): 71-83%
// Zone 4 (Orange): 84-91% (The "Splat" Zone)
// Zone 5 (Red): 92-100%
var z1_min = Math.round(maxHeartRate * 0.50);
var z1_max = Math.round(maxHeartRate * 0.60);
var z2_min = Math.round(maxHeartRate * 0.61);
var z2_max = Math.round(maxHeartRate * 0.70);
var z3_min = Math.round(maxHeartRate * 0.71);
var z3_max = Math.round(maxHeartRate * 0.83);
var z4_min = Math.round(maxHeartRate * 0.84);
var z4_max = Math.round(maxHeartRate * 0.91);
var z5_min = Math.round(maxHeartRate * 0.92);
var z5_max = maxHeartRate; // Can go higher in reality, but capped at 100% for theoretical range
var tableHtml = `
Understanding the science behind the workout is key to getting the most out of your Orangetheory Fitness (OTF) experience. The core of the OTF workout revolves around Heart Rate Based Interval Training, where your effort is categorized into five distinct color zones.
The Evolution of the Formula
For many years, the standard calculation used by fitness professionals and OTF alike was the Fox Formula: 220 minus your age. While simple, this formula has been criticized for being too generalized and often inaccurate for older adults or fit individuals.
Orangetheory has since updated its algorithm to provide a more tailored experience. For new members, the system typically utilizes the Tanaka Formula (or a very similar variation), which is widely considered more accurate for a broader population.
The Tanaka Formula:
Max HR = 208 – (0.7 × Age)
The 5 Heart Rate Zones Explained
Once your Maximum Heart Rate (MHR) is established, OTF calculates your zones based on percentages of that number.
Zone 1 (Gray): 50-60% of MHR. This is your recovery zone, usually occurring before class starts or during transitions.
Zone 2 (Blue): 61-70% of MHR. This is your warm-up zone. You should feel comfortable here.
Zone 3 (Green): 71-83% of MHR. Known as "Base Pace," this is a challenging but doable pace you can maintain for 20-30 minutes. It is the primary zone for fat burning.
Zone 4 (Orange): 84-91% of MHR. This is "Push Pace." You are uncomfortable and utilizing anaerobic energy. This is where the magic happens—earning "Splat Points" to trigger the Afterburn effect (EPOC).
Zone 5 (Red): 92-100% of MHR. This is "All Out." You should only be here for short bursts (30-60 seconds).
What are Splat Points?
A "Splat Point" is earned for every minute you spend in the Orange or Red zones. Orangetheory's philosophy is based on Excess Post-Exercise Oxygen Consumption (EPOC). The goal is to accumulate 12 or more Splat Points during the hour-long class to maximize metabolic burn for up to 24 hours after the workout.
Automatic Adjustments
If you find that you are constantly in the Red zone without feeling exhausted, or conversely, cannot get out of the Green zone despite maximum effort, your Max HR setting may be inaccurate. Orangetheory's system now automatically scans your performance data after every 20 classes. If your actual heart rate data suggests your max is higher or lower than the age-predicted baseline, the system will adjust your zones to ensure your workout data matches your perceived effort.