Distance & finish time
Hours
Minutes
Seconds
Pace per kilometre
—
per km
—Pace per mile
—Speed (km/h)
—Speed (mph)
—Finish time
Predicted race times (Riegel formula)
For guidance only — not financial, tax or legal advice. Verify with a qualified professional.
Running pace — frequently asked questions
How is running pace calculated?
Running pace is simply total time divided by distance. If you run 5 kilometres in 30 minutes, your pace is 30 ÷ 5 = 6 minutes per kilometre (6:00/km). To convert to pace per mile, multiply pace per km by 1.60934. Pace helps you train consistently and plan race strategy more effectively than tracking speed alone.
What is the Riegel formula and how accurate is it?
The Riegel formula — T2 = T1 × (D2 ÷ D1)^1.06 — predicts your finish time at a new distance based on a known performance. The exponent 1.06 accounts for the physiological "fatigue factor": you naturally slow down as distance increases. It's most accurate within roughly 2× of your reference distance and assumes similar conditions (flat course, good weather, well-rested). It can slightly overestimate marathon times for runners who haven't done the specific endurance training for that distance.
What are common training pace zones?
Most runners train across five zones. Easy / Zone 2 (65–75% max HR) is conversational pace — this should be 80% of your running. Tempo / Zone 3–4 (80–90% max HR) is comfortably hard and builds lactate threshold. Intervals / Zone 5 (90–100% max HR) are short, fast efforts that build VO2 max. A simple rule: your easy pace should be 60–90 seconds per km slower than your 5K race pace. Running too fast on easy days is the most common training mistake.
What are negative splits and why do they matter?
Negative splitting means running the second half of a race faster than the first. It's the optimal pacing strategy for most distances because it prevents early glycogen depletion and muscle damage. Starting too fast — even by 5–10 seconds per km — often leads to dramatic slowdowns in the final third of a race. Aim to run the first half 1–2% slower than goal pace, then gradually increase effort as you feel strong.
What are typical race paces for different ability levels?
For a 5K: beginners typically finish in 30–40 minutes (6:00–8:00/km), intermediates in 22–30 minutes (4:24–6:00/km), and advanced runners under 20 minutes (sub 4:00/km). For a marathon: beginners aim for 4:30–5:30 finish (6:24–7:49/km), intermediates 3:30–4:30 (4:59–6:24/km), and advanced runners target sub-3:00 (sub 4:16/km). These are broad guidelines — your own performance relative to your training history is the best predictor.