Power Zone Calculator: Find Your Training Zones

A power zone calculator takes your functional threshold power (FTP) and returns your seven training zones, from active recovery to neuromuscular power. You enter your FTP in watts, and the calculator outputs the wattage ranges for each zone, which you can use to structure indoor and outdoor cycling workouts. This page explains the standard Coggan power zone model, shows you how to use the calculator, and covers common pitfalls.

Formula

The power zone calculator uses the seven-zone model popularized by Dr. Andrew Coggan, a sports scientist and cycling coach. Each zone is defined as a percentage of your functional threshold power (FTP), which is the highest average power you can sustain for about one hour. The formulas are:

• Zone 1: 0.55 × FTP (less than 55% of FTP)
• Zone 2: 0.56–0.75 × FTP (56–75% of FTP)
• Zone 3: 0.76–0.90 × FTP (76–90% of FTP)
• Zone 4: 0.91–1.05 × FTP (91–105% of FTP)
• Zone 5: 1.06–1.20 × FTP (106–120% of FTP)
• Zone 6: 1.21–1.50 × FTP (121–150% of FTP)
• Zone 7: >1.50 × FTP (more than 150% of FTP)

The calculator above shows the upper bound of each zone for simplicity, but in practice each zone is a range. For example, Zone 2 is everything between 56% and 75% of your FTP. The first output (Zone 1) is the top of that zone; the next output is the top of Zone 2, and so on.

Worked Example

Let’s use the default FTP of 250 watts. Here’s how the calculator computes each zone:

• Zone 1: 250 × 0.55 = 137.5 watts (top of Zone 1)
• Zone 2: 250 × 0.75 = 187.5 watts (top of Zone 2)
• Zone 3: 250 × 0.90 = 225 watts (top of Zone 3)
• Zone 4: 250 × 1.05 = 262.5 watts (top of Zone 4)
• Zone 5: 250 × 1.20 = 300 watts (top of Zone 5)
• Zone 6: 250 × 1.50 = 375 watts (top of Zone 6)
• Zone 7: 250 × 1.75 = 437.5 watts (top of Zone 7)

So with an FTP of 250 W, your endurance zone (Zone 2) is roughly 140–188 watts, your tempo zone (Zone 3) is 190–225 watts, and your threshold zone (Zone 4) is 228–263 watts. These ranges are what you’d target during specific workouts.

What Is Functional Threshold Power (FTP)?

FTP is the highest average power you can hold for 60 minutes. In practice, most cyclists don’t do a full-hour test; they do a 20-minute all-out effort and multiply the average power by 0.95 to estimate FTP. For example, if your 20-minute average is 260 W, your estimated FTP is 247 W. The power zone calculator assumes you already have an FTP value, either from a test or from a recent race. If you don’t have a power meter, you can estimate FTP from a heart-rate threshold test, but power zones are more precise for training.

How to Use the Power Zone Calculator

To get useful zones, follow these steps:

1. Find your FTP – Do a 20-minute time trial or use a recent race average. Multiply the 20-min average by 0.95 to get FTP.
2. Enter your FTP – Type the number in watts into the calculator. It accepts values from 50 to 1500 watts, which covers nearly all cyclists.
3. Read the zone ranges – The outputs show the top of each zone. For example, if your FTP is 200 W, Zone 2 tops out at 150 W, so your endurance range is 112–150 W.
4. Use the zones in workouts – Match your workout goals to the zones. For example, endurance rides should stay in Zone 2, while interval sessions might touch Zone 5 or 6.

Common Mistakes and Misconceptions

One common mistake is treating the zone boundaries as exact numbers. The percentages are guidelines, not hard cutoffs. A few watts above or below a boundary won’t ruin a workout. Another mistake is using outdated FTP values. Your FTP changes with fitness, so retest every 4–6 weeks and update your zones. Also, don’t confuse power zones with heart-rate zones. Power is a direct measure of work, while heart rate lags behind effort and is affected by fatigue, heat, and caffeine. Finally, many people think Zone 2 is “too easy,â€� but it’s the foundation of endurance training. If you always ride in Zone 3 or higher, you may miss the aerobic adaptations that come from time in Zone 2.

Limitations of the Power Zone Model

The Coggan zones are based on a single percentage of FTP, but they don’t account for individual differences. For example, a sprinter might have a much higher anaerobic capacity (Zone 6) relative to FTP than a time trialist. The zones are also less accurate for very short efforts (under 10 seconds) and very long efforts (over 2 hours). For ultra-endurance events, some coaches use a different model based on a 4-hour threshold. Additionally, the calculator gives you the top of each zone, but the actual zone includes everything from the previous boundary up to that number. For instance, Zone 4 is 91–105% of FTP, so with FTP 250 W, Zone 4 is 228–263 W, not just 263 W.

Alternatives to Power Zones

If you don’t have a power meter, you can train with heart-rate zones, which are calculated from your maximum heart rate or lactate threshold heart rate. Another option is rate of perceived exertion (RPE), where you rate effort on a scale of 1–10. For example, Zone 2 feels like a 3–4 out of 10, while Zone 5 feels like 8–9. Some training platforms use a “Training Stress Scoreâ€� (TSS) that combines power and duration to quantify workout load, but that requires a power meter and a head unit or app. The power zone calculator is a simple starting point, but many cyclists combine power zones with heart-rate and RPE to get a fuller picture of their training.

Frequently Asked Questions

How do I test my FTP?

The most common method is a 20-minute all-out effort after a proper warm-up. Warm up for 15–20 minutes with a few short sprints, then ride as hard as you can for 20 minutes. Take the average power from that 20 minutes and multiply by 0.95 to estimate your FTP. For example, if your 20-min average is 240 W, your FTP is 228 W.

What if my FTP is not a round number?

That’s fine. The calculator accepts decimals, and the zone outputs will also show decimals. You can round to the nearest 5 watts when setting your training zones, but it’s not necessary.

Can I use power zones without a power meter?

You can, but you’ll need to estimate your FTP from a heart-rate threshold test or from a recent race result. Without a power meter, you can’t see real-time power, so you’d have to rely on heart rate or perceived exertion to stay in the right zone. A power meter is recommended for precise training.

How often should I update my FTP?

Retest every 4–6 weeks, especially if you’re following a structured training plan. If you notice that your usual power for a given effort feels easier, it may be time to retest. Updating your FTP ensures your zones stay accurate as your fitness improves.

Are the zones the same for indoor and outdoor cycling?

Yes, the zones are based on power, which is the same regardless of where you ride. However, indoor riding often feels harder due to heat and lack of airflow, so you might need to adjust your expectations for a given zone. Use a fan and keep hydration handy.

What is the difference between Zone 4 and Zone 5?

Zone 4 is around your FTP (91–105%), which you can sustain for roughly 30–60 minutes. Zone 5 is above FTP (106–120%), which you can only hold for about 3–8 minutes per interval. Zone 4 builds threshold power, while Zone 5 improves VO2 max and aerobic capacity.

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in ftp | Functional Threshold Power (FTP) | watts | 250 | 50 | 1500
out z1 | Zone 1: Active Recovery | watts | ftp * 0.55 | 0
out z2 | Zone 2: Endurance | watts | ftp * 0.75 | 0
out z3 | Zone 3: Tempo | watts | ftp * 0.90 | 0
out z4 | Zone 4: Lactate Threshold | watts | ftp * 1.05 | 0
out z5 | Zone 5: VO2 Max | watts | ftp * 1.20 | 0
out z6 | Zone 6: Anaerobic Capacity | watts | ftp * 1.50 | 0
out z7 | Zone 7: Neuromuscular Power | watts | ftp * 1.75 | 0