Free calculator

Half Marathon Pace Calculator

Enter your half marathon goal time and instantly see your required race pace plus all four VDOT training zones — easy, tempo, speed, and long run.

Enter your half marathon goal time

HH
:
MM

Goal race pace

5:41/km

Training zones

Easy

Aerobic base — fully conversational

7:07/km–6:26/km

Zone 2 · 65–75% HRmax

Tempo

Lactate threshold — 2–3 words only

5:17/km–5:04/km

Zone 3–4 · 76–88% HRmax

Speed

VO₂max intervals — hard repetitions

4:57/km–4:43/km

Zone 5 · 92–100% HRmax

Long Run

Time on feet — easy throughout

7:07/km–6:32/km

Zone 2 · 65–75% HRmax

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Common questions

What is a good half marathon pace?

A good half marathon pace is one you can sustain for the full 21.1 km — typically around your lactate threshold effort. For most recreational runners this is 5:00–8:30/km (8:03–13:41/mi). The key is consistency: even splits or a slightly negative split (faster second half) produce better results than starting too fast.

How do I use training zones from my half marathon goal time?

Easy runs should be run at 1.13–1.25× your goal HM pace — significantly slower than race pace. Tempo runs at 0.89–0.93× — faster than race pace, sustainable for about 20–40 minutes. Speed intervals at 0.83–0.87× — near VO₂max effort, run in short repetitions. The training zones tell you exactly how hard each session should feel.

Why are my easy run paces so much slower than my race pace?

Because easy runs and races serve completely different physiological purposes. Easy runs build mitochondrial density and fat oxidation — adaptations that only happen at low intensity. Running easy runs too fast means you arrive at quality sessions already tired, and the hard sessions don't produce the right adaptation. The gap feels counterintuitive but is supported by decades of exercise physiology research.

How accurate are these training zones?

The zones are derived from Jack Daniels' VDOT methodology, which is based on VO₂max research and validated across thousands of runners. They're accurate when your goal time reflects your current fitness — not an aspirational target. If your goal time is significantly faster than your recent race performance, use your current fitness as the input for more accurate zones.

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