Heart Rate Zone Calculator (Zones 1-5)

Use the Heart Rate Zone Calculator

Generate Zones 1–5 from Max HR, Heart Rate Reserve (Karvonen), or Lactate Threshold with this heart rate zones calculator.

Calculate your training zones

How to Use Heart Rate Zone Calculator (Zones 1-5)

1. Step 1: Choose Method

   Select Max HR, Heart Rate Reserve (HRR), or Lactate Threshold (LTHR) as your zone source.

2. Step 2: Enter Inputs

   Provide age or known Max HR. For HRR, also enter Resting HR. For LTHR, enter your threshold HR.

3. Step 3: Pick Formula (optional)

   If estimating Max HR from age, choose Tanaka (208 − 0.7×age) or Fox (220 − age).

4. Step 4: Calculate Zones

   Tap Calculate Zones to generate Zones 1–5 with bpm ranges and tips.

5. Step 5: Plan Your Week

   Add weekly minutes and choose Polarized, Pyramidal, or Balanced to see suggested time‑in‑zone.

6. Step 6: Save & Train

   Screenshot your zones or note them for workouts. Re‑check every 2–4 weeks.

Key Features

• Multiple zone models
• LT/FTP option
• Weekly zone time
• Tips for each zone

Understanding Results

Heart rate zone calculator tips

Base most endurance on Zones 1–2, verify threshold with a steady 20–30 minute effort, and retest zones every few weeks. Pair bpm with perceived exertion and breathing to adapt for heat, altitude, or fatigue.

Formula

This tool supports three common models. With Max HR (MHR), zones are a percentage of your maximum: Zone 1 = 50–60% MHR, Zone 2 = 60–70%, Zone 3 = 70–80%, Zone 4 = 80–90%, Zone 5 = 90–100%. With Heart Rate Reserve (HRR), the Karvonen method adjusts for your Resting HR (RHR): Target HR = RHR + % × (MHR − RHR). With Lactate Threshold HR (LTHR), zones are set relative to the effort you can hold near threshold (e.g., Zone 3 ≈ 95–99% LTHR, Zone 4 ≈ 100–102%).

If you do not know MHR, the calculator can estimate it from age using Tanaka (208 − 0.7×age) or Fox (220 − age). These are population formulas; your true MHR may differ by ±10–12 bpm or more.

Reference Ranges & Interpretation

Use Zones 1–2 for the bulk of endurance training—easy, conversational efforts that build aerobic capacity with low strain. Zone 3 (tempo) develops steady‑state stamina. Zone 4 targets threshold—sustained hard efforts that raise the pace you can hold before fatigue accelerates. Zone 5 is very hard VO₂ max work; use sparingly in short intervals once you have a base.

Because hydration, heat, altitude, and fatigue affect HR, pair zones with perceived exertion (RPE) or the talk test. If you breathe only through your nose or can speak in short sentences, you are likely in Zones 1–2; if speech is limited to single words, you are near Zones 4–5.

Assumptions & Limitations

Heart rate varies day to day and rises with heat, dehydration, and stress. Medications (for example, beta‑blockers) can lower MHR and suppress response. Wrist sensors may lag during intervals; a chest strap is more reliable. Treat results as training guidance, not medical advice, and adapt zones as your fitness changes.

Complete Guide: Heart Rate Zone Calculator (Zones 1-5)

Get Zone 1–5 targets from Max HR or lactate threshold. This heart rate zone calculator (heart rate zones calculator) optimizes endurance with training ranges.

Training with zones is a simple way to guide effort, manage fatigue, and build aerobic fitness without overthinking the science. The calculator above turns a few numbers—age, resting heart rate, or a threshold effort—into clear Zone 1–5 targets for your next workout.

How heart rate zones work

Zones split intensity into five useful buckets. Rather than chasing a single pace each day, you make most sessions easy (Zones 1–2), add steady tempo or threshold work (Zone 3–4), and sprinkle in short, fast repeats (Zone 5) once you have a base. Because heart rate reflects internal load, it remains helpful across terrain changes, wind, and even treadmill sessions.

There is no universal “best” scheme, but three methods are common: percentages of Max Heart Rate (MHR), Heart Rate Reserve (HRR/Karvonen), and percentages of Lactate Threshold HR (LTHR). All three can guide training effectively if you apply them consistently and update inputs periodically.

Choosing a model: MHR vs HRR vs LTHR

MHR % is straightforward and widely used: Zone 2 is 60–70% of MHR, Zone 3 is 70–80%, and so on. The downside is that two people with different resting heart rates may experience different difficulty at the same percentage of MHR.

HRR (Karvonen) accounts for Resting HR (RHR): Target HR = RHR + % × (MHR − RHR). If your RHR is low from high aerobic fitness, HRR tends to produce zones that feel more tailored than raw MHR percentages.

LTHR % anchors zones to a hard, sustained effort you can maintain near threshold (often close to your 40–60‑minute race effort). Many endurance athletes like LTHR because it ties training directly to performance‑relevant intensity. If you have a recent threshold test or a solid field estimate, this is a strong choice.

Not sure where to start? Try HRR if you know your resting HR; try LTHR if you can do a simple threshold field test. Otherwise, begin with MHR and switch later if you need more personalization.

Estimating Max HR safely

If you do not know your MHR, start with an age‑based estimate. The two common formulas are Fox (220 − age) and Tanaka (208 − 0.7×age). Population formulas are convenient but imprecise—expect a meaningful error band. If you prefer, estimate today and refine later with real workouts.

You can also head to our quick tools to cross‑check or prep a workout: use the Max Heart Rate Calculator and the Heart Rate Calculator for warm‑up/cool‑down targets. Planning a run? Set paces with the 5K Pace Calculator or Marathon Pace Calculator.

Finding Lactate Threshold HR

A practical field method: Warm up 10–15 minutes, then go hard but sustainable for 30 minutes. Record average HR for the final 20 minutes—that approximates LTHR for your sport. Conditions matter, so repeat on a similar route when you can. If you prefer a lab test, a professional can measure threshold with blood lactate or gas exchange.

For context on aerobic capacity, you can also estimate VO₂ max from a recent race with our VO₂ Max Calculator. While VO₂ max and LTHR measure different things, both help you choose suitable intensities and track progress.

Zone 2 training guide

Zone 2 (endurance) sits just below your first noticeable rise in breathing rate; you can speak in short sentences and feel steady for a long time. This is where much of the aerobic magic happens—mitochondrial density, capillary growth, and improved fat oxidation. A simple weekly plan might include 2–4 Zone 2 sessions of 30–90 minutes each, depending on your background and schedule.

New or returning to training? Start with three Zone 2 sessions a week, 20–40 minutes each, plus one short session that adds 2–4 × 1 minute at Zone 4 with easy recoveries. As you adapt, increase total minutes before adding more intensity. If you cross‑train, set separate zones for running and cycling because bpm can differ.

Polarized vs pyramidal weekly plans

The calculator’s weekly planner suggests Zone 1–5 minutes from your total weekly time using a preset distribution. Polarized (≈80/20) puts the vast majority of work in Z1–Z2 and a small portion in Z4–Z5; Pyramidal uses the most time in Z1, less in Z2, and progressively smaller chunks in higher zones. Balanced spreads time across all five zones for general fitness. Whichever you choose, keep easy days truly easy so the hard days can be honest.

If you need to translate intensity to pace or speed—for treadmill runs, treadmill miles per hour, or cycling—pair your zones with our planning tools: the Endurance Calculator handles time/pace/distance, and the Calories Burned Calculator offers simple energy estimates for longer days.

Adjusting for heat, hills, and drift

Heart rate rises over a session—especially in heat or during long intervals—even if power or pace stays constant. This “cardiac drift” is normal. On hot or hilly days, keep your RPE aligned with the intended zone and allow the bpm to drift a little. If you often train in heat, shift zone ceilings down slightly or shorten intervals to keep the quality.

Good habits help: hydrate, fuel early on long sessions, and warm up gradually. A chest strap is more responsive than a wrist sensor for short intervals; if your watch lags by 10–20 seconds, extend recoveries or use slightly longer intervals so the signal catches up.

Safety, meds, and red flags

Some medications—such as beta‑blockers—reduce heart rate response, which can make MHR and HRR zones read artificially low. In those cases, perceived exertion and the talk test become even more important. If you have a cardiovascular condition or are new to exercise, speak with a clinician before intense training.

Stop a session and seek medical help if you experience chest pain, unusual shortness of breath, dizziness, or fainting. For general exercise guidance, see the U.S. Physical Activity Guidelines from the HHS/ODPHP and practical advice on hydration and heat safety from the CDC.

Next steps: plan your training

1) Generate your zones, 2) set weekly minutes, 3) pick a distribution—polarized, pyramidal, or balanced—and 4) map the week. Keep most days in Zone 2, then add one quality day at Zone 3–4 and a short session with Zone 5 strides or repeats if you are healthy and recovered. Revisit the plan each week and adjust by how you feel.

When you’re ready to sharpen goals, combine tools: use the VO₂ Max Calculator to benchmark aerobic capacity, dial in paces with the Endurance Calculator, and update your zones as fitness improves.

Frequently Asked Questions