Pace Calculator
Solve for pace, time, or distance. 5K, 10K, half, marathon, and any custom distance. Splits table included.
Runs entirely in your browser. Nothing is sent to our servers.
About this tool
Three calculations in one: solve for pace, finish time, or distance given any two of the three. Useful for race planning, training, or just figuring out how fast you'd need to go to break a specific time.
Common race distances
Use the quick-reference buttons for standard distances. A few extras worth knowing:
- 5K = 5 kilometres (3.107 miles)
- 10K = 10 km (6.214 miles)
- Half marathon = 21.0975 km (13.109 miles)
- Marathon = 42.195 km (26.219 miles)
- 50 mile ultra = 80.467 km
- 100 km ultra = 62.137 miles
Pace and speed
The output shows pace (min/km, min/mile) and speed (km/h, mph) side by side. Most runners think in pace; cyclists usually think in speed. Treadmills usually display speed, so the conversion is handy when matching a runner's planned pace to the treadmill setting.
Frequently asked questions
- What's a "good" pace for a beginner?
- For a complete beginner doing a 5K, finishing at any pace is the goal — typical first-time finishers come in around 30–40 minutes. Recreational runners often target 25–30 min for 5K; trained recreational runners 20–25; competitive runners under 20.
- How do I convert my treadmill speed to pace?
- Punch the treadmill speed (e.g. 10 km/h) into the "speed" interpretation of your numbers, or use the calculator with distance = 1 km and back into the time at that speed. 10 km/h = 6:00 min/km pace.
- What about elevation, wind, heat?
- Pace calculators are flat-ground neutral-conditions math. Hills slow you down by roughly 12–15 seconds per km per 100 m of climb (and you get most but not all of it back going down). Heat and headwinds also slow you. Adjust your expectations.
- Are these times the same on a track and on the road?
- A 400m track lap is exactly 400m in the inside lane. Road-measured kilometres are the same length, but GPS watches typically over-read by 1–3% on twisty courses (urban runs, trails). Run on a measured course or track for a true comparison.
Last updated: May 17, 2026