Pace Calculator
Solve pace, finish time, or distance — with 5K-to-marathon race predictions, even-pace splits, and a PDF race plan.
hours
min
sec
💡 Works for running, jogging, walking, and cycling. Race predictions use Riegel's formula from your entered effort.
Your pace over 5K
5:36 /km
min/km
5:36
min/mile
9:01
km/h
10.7
mph
6.7
🏁 What this effort predicts for race day
Riegel's formula: T₂ = T₁ × (D₂/D₁)^1.06 — assumes you train appropriately for the longer distance.
5K · your effort
28:00
5:36 /km · 9:01 /mi
10K
58:23
5:50 /km · 9:24 /mi
Half marathon
2:08:48
6:06 /km · 9:50 /mi
Marathon
4:28:33
6:22 /km · 10:15 /mi
📋 Even-pace splits (5K at 5:36/km)
| Split | Lap time | Cumulative |
|---|---|---|
| 1 km | 5:36 | 5:36 |
| 2 km | 5:36 | 11:12 |
| 3 km | 5:36 | 16:48 |
| 4 km | 5:36 | 22:24 |
| 5 km | 5:36 | 28:00 |
Write these on your arm or set them on your watch — even pacing beats fast starts in almost every race.
⚠️ Predictions assume similar conditions and appropriate training for the distance — treat them as targets, not guarantees.
👟Pace, time, or distance — solve any of the three
Pace, time, and distance form a triangle: know any two and the third follows. This calculator solves all three directions — find your pace from a run, predict a finish time from a target pace, or work out how far you went. Every answer comes with instant conversions (min/km, min/mile, km/h, mph), race-day predictions for 5K to marathon using Riegel's formula, and an even-pace split table you can download as a PDF race plan.
📊Everything you'd want to know
- Three solve modes: pace from distance + time, finish time from distance + pace, distance from time + pace.
- One-tap race presets — 5K, 10K, half marathon (21.0975 km), marathon (42.195 km) — or any custom distance.
- Kilometres or miles everywhere, with all four speed/pace conversions shown side by side.
- Race predictions from your current effort via Riegel's formula (used by coaches worldwide).
- A full splits table at even pacing — per km or per mile — with lap and cumulative times.
- A branded PDF race plan with your splits and predictions.
🧮The science
Riegel's exponent 1.06 captures how speed naturally fades as distance grows — you can't hold 5K pace for a marathon. Doubling the distance costs about 8% more than double the time. The formula is remarkably accurate between 5K and the marathon for runners who train for the target distance.
💡Race-day pacing tips
- Even or slightly negative splits (second half faster) beat a fast start in almost every race ever studied.
- The first km should feel too easy — adrenaline lies at the start line.
- Check your watch at each split against the plan; correct gently, never suddenly.
- For beginners: run-walk intervals (e.g. 4 min run / 1 min walk) often produce faster finishes than running non-stop.
💡 Frequently Asked Questions
What is running pace and how is it calculated?+
Pace is time per unit distance, usually min:sec per km or per mile — total time divided by distance. Running 5 km in 28 minutes is 5:36 min/km, which equals about 10.7 km/h. This tool converts between all four formats automatically.
What's a good pace for beginners?+
Around 7:00–8:30 min/km is a solid beginner running pace, and brisk walking is roughly 10–12 min/km. Consistency matters far more than speed at the start — most plans build distance first, speed later.
How accurate are the race time predictions?+
Riegel's formula is typically within a few percent between 5K and marathon — if you train appropriately for the longer distance. Predicting a marathon from a 5K assumes you build the endurance base; without long runs, real results will be slower.
What are splits and why do they matter?+
Splits are your time for each km or mile of a race. Racing at even splits — the same pace throughout — is the most efficient strategy; starting too fast costs more time at the end than it saves at the start. The table gives you exact cumulative times to check at every marker.
Does this work for walking and cycling too?+
Yes — the pace/time/distance triangle is the same for any steady activity. The Riegel race predictions are calibrated for running, so treat them as rough guides for walking or cycling.