Marathon in 240 min pace
Here’s the pace and predicted race times for a marathon in 240 min.
Different time or distance? Use the full pace calculator above.
About the pace calculator
Pace is simply speed expressed the way runners think about it — time per unit of distance rather than distance per unit of time. This calculator divides your total time by your distance to get seconds per mile or seconds per kilometer, then formats that as a familiar minutes:seconds pace, since "7:45 per mile" is far easier to use for pacing a run than a raw decimal speed figure.
Because races and training plans mix units depending on where you are, the calculator converts between mile pace and kilometer pace automatically using the exact conversion 1 mile = 1.60934 kilometers. Enter your distance in whichever unit you tracked it in, and both pace figures are shown side by side so you don't have to convert by hand mid-run or mid-plan.
Beyond your current pace, the calculator also projects finish times at four common race distances — 5K, 10K, half marathon (21.0975 km), and marathon (42.195 km) — using Riegel's race-time prediction formula: predicted time = current time × (predicted distance ÷ current distance)^1.06. This formula, developed by Pete Riegel in 1977, captures the well-observed fact that pace naturally slows over longer distances due to endurance and fueling demands, rather than assuming you could hold your current pace indefinitely.
Riegel's exponent of 1.06 is an average derived from race performance data across many runners and distances — it works best when predicting a similar distance to the one you entered (for example, predicting a 10K time from a 5K time) and gets less reliable across very large distance jumps, such as predicting a marathon time from a single mile time trial, where pacing, fueling, and endurance factors diverge more from short-distance sprinting.
Use this calculator to check your current training pace, convert a race pace between miles and kilometers, or get a realistic target time for an upcoming race based on a recent performance at a different distance. It's a planning estimate, not a guarantee — actual race results depend on course terrain, weather, pacing strategy, and race-day conditioning.
Pace calculator questions
How pace and Riegel race-time predictions are calculated.
How do I calculate my running pace?
Divide your total time by your distance. Enter your distance (in miles or kilometers) and your total time, and the calculator divides the two to show your pace as minutes and seconds per mile and per kilometer.
How do I convert pace from minutes per mile to minutes per kilometer?
Multiply your per-mile pace by 0.62137 (or divide by 1.60934) to get pace per kilometer, since 1 mile equals 1.60934 kilometers. This calculator converts both directions automatically.
What is Riegel's formula for predicting race times?
Riegel's race-time prediction formula estimates a finish time at a new distance from a known time at another distance: predicted time = current time × (predicted distance ÷ current distance)^1.06. It accounts for the natural slowdown in pace over longer distances.
How accurate are race time predictions from a shorter distance?
They're most accurate when predicting a nearby distance — for example, using a 10K time to predict a half marathon. Predictions across very different distances (like a mile time predicting a marathon) are less reliable, since endurance and fueling become bigger factors at longer distances.
What is a good 5K pace?
It varies widely by fitness level, but a 25-minute 5K is roughly an 8:03/mile (5:00/km) pace, while a 20-minute 5K is about 6:26/mile (4:00/km). Enter your own 5K time into the calculator to see your exact pace and projected times at other distances.
How do I find my marathon pace from my current training pace?
Enter your current distance and time into the calculator — the predicted marathon time uses Riegel's formula to estimate a realistic marathon pace based on your current fitness, adjusted for the natural pace decline over 42.195 km.