Solve for pace, time or distance, compute checkpoint-to-checkpoint splits, convert between 8 pace/speed units, or project your finish time mid-race — four tools in one, metric and imperial.
Splits
| Km | Split | Cumulative |
|---|
🔮 Predicted Race Times
Enter your details to calculate pace
This pace calculator is a four-in-one running toolkit that doubles as a running pace calculator, race pace calculator, marathon pace calculator, and 5K pace calculator all in one place: solve for pace, time, or distance from the other two; break a race into checkpoint splits with the multipoint pace calculator tab; convert a pace or speed value between 8 different units with the built-in pace converter; and project a finish time mid-run with the finish time calculator. It's built for runners planning race strategy, tracking training paces, or converting a treadmill speed into a familiar min per km or min per mile pace.
Pace is the time it takes to cover a fixed distance — usually expressed in minutes and seconds per kilometer or per mile — while speed measures how far you travel in a fixed time (km/h or mph). This calculator's core engine applies pace = time ÷ distance and its algebraic rearrangements to solve for whichever value you're missing, then layers on splits, unit conversions, and race-time predictions built from that same core relationship.
This tool is designed for recreational and competitive runners, run coaches, and anyone training for a 5K, 10K, half marathon, or marathon. It's equally useful for a beginner converting a treadmill's mph display into a familiar pace, and for an experienced racer planning even splits and a target finish time ahead of race day.
Pacing well is one of the biggest controllable factors in race performance — starting too fast is one of the most common ways runners fade late. Splits and finish-time projections let you check whether you're on pace mid-race, while the pace converter and Riegel predictions help translate a known performance (say, a 5K time) into a pacing plan for a different distance or a different unit system.
How each of this calculator's four tools computes its results
Internally, every distance is converted to kilometers (1 mile = 1.60934 km, 1 yard = 0.0009144 km) and every pace/speed unit is converted to seconds-per-kilometer before any math happens, so the same core formulas power the Main, Multipoint, Converter, and Finish Time tools consistently.
Pace is how long it takes to cover a fixed distance (minutes per km/mile) — lower is faster. Speed is how far you travel in a fixed time (km/h or mph) — higher is faster. Runners typically think in pace; cyclists and drivers typically think in speed.
Running each km or mile at the same pace ("even splits") is generally the most efficient race strategy — it avoids the energy cost of surging early and fading late. The splits table assumes a constant pace throughout the entered distance.
Predicted times at 5K, 10K, 15K, Half Marathon, and Marathon use Riegel's formula: T2 = T1 × (D2 ÷ D1)^1.06. It estimates how your current fitness translates to other distances, assuming similar training and conditions. Accuracy drops for very different distances (e.g. predicting a marathon from a 1-mile time).
The Multipoint tool subtracts each checkpoint's cumulative distance and time from the previous one (segment distance = current − previous) to isolate the pace of that specific segment, revealing exactly where you sped up or slowed down.
The Converter treats pace and speed as mathematical reciprocals: speed (km/h) = 3600 ÷ pace (sec/km), and pace (sec/km) = 3600 ÷ speed (km/h). Every one of the 8 units is derived from this single relationship after converting to a common unit.
Finish Time takes your pace so far (elapsed time ÷ distance covered) and multiplies it by the full race distance — a simple linear scaling with no fatigue adjustment, unlike the Riegel formula used for cross-distance predictions.
From choosing a value to solve for, to reading your splits and predictions
On the main tab, pick Pace, Time, or Distance from the Calculate dropdown depending on which value you want to solve for.
Fill in the other two fields — for example, distance and time if you're solving for pace — choosing metric or imperial units as needed.
The calculator applies pace = time ÷ distance (and its rearrangements) to compute your result instantly.
See your pace in multiple units, a per-km splits table and chart, and Riegel-formula predicted race times for other common distances.
Switch to Multipoint for checkpoint-to-checkpoint splits, Converter to translate a pace or speed into 8 units at once, or Finish Time to project a mid-race finish.
Using the Main tab's own default scenario — 5 km in 25:00
Suppose you're solving for Pace, and you enter a distance of 5 km with a total time of 25 minutes (0:25:00).
Explanation: A flat 5:00/km pace (8:03/mi, 12.00 km/h) over 5 km produces perfectly even 5:00 splits since the distance divides evenly into whole kilometers. Note how the Riegel formula's 1.06 exponent means predicted pace slows gradually at longer distances — the naive linear guess for a marathon would be 25:00 × 8.439 ≈ 3:31:00, but Riegel's fatigue adjustment predicts a more realistic 3:59:47, almost 29 minutes slower, which better matches how endurance performance actually degrades over distance.
Finish Time tool example (same 5:00/km pace): With 5 km covered in 25:00 and a full race distance of 10 km entered, current pace = 1,500 ÷ 5 = 300 sec/km, predicted finish = 300 × 10 = 3,000 sec = 50:00, and remaining distance/time = 5 km / 25:00 — this uses simple linear scaling rather than the Riegel fatigue adjustment, since it's projecting the same run rather than a different race distance.
General training-pace zones and what they're typically used for
| Effort Level | Typical Use | General Guidance |
|---|---|---|
| Easy / conversational pace | Base training, recovery runs | Should feel comfortable enough to hold a conversation; makes up most weekly training volume |
| Marathon / steady pace | Long runs, marathon race pace | Comfortably hard, sustainable for hours; a common target for the Finish Time and Riegel predictions |
| Threshold / tempo pace | Tempo runs, half marathon race pace | Sustainable for roughly 30-60 minutes; noticeably harder to hold a conversation |
| Interval / 5K-10K pace | Speed work, shorter race pace | Hard, sustainable only for several minutes at a time; used in structured interval sessions |
| Sprint / all-out pace | Sprint intervals only | Maximal effort, sustainable for well under a minute; not representative of race pacing |
If your calculated pace matches an easy or marathon-effort zone: it's likely sustainable for the training run or long race distance you're planning — this is the pace zone most training plans emphasize.
If your calculated pace falls in the threshold or interval zones: treat it as a shorter-duration target rather than something to hold for a full race, since these efforts aren't designed to be sustained for hours.
This result is for informational purposes only and is not a medical diagnosis. Pace and finish-time projections are mathematical estimates based on the numbers you enter, not a guarantee of race-day performance — actual results vary with fitness, training, terrain, weather, and pacing strategy.
This calculator provides educational estimates only and should not be used as a substitute for professional medical advice, diagnosis, or treatment. Results may vary depending on individual health conditions. Always consult a qualified healthcare professional regarding medical concerns.
Safety note: Pushing to a new pace or distance too quickly raises the risk of overuse injury. Increase weekly mileage and race distance gradually, warm up before hard efforts, stay hydrated, and stop or slow down if you experience chest pain, dizziness, or unusual shortness of breath. If you're new to running or returning after injury, check with a healthcare professional before starting a race-pace training plan.
Where a fast, flexible running pace calculator is genuinely useful
Work out the exact pace needed to hit a goal finish time for a 5K, 10K, half, or full marathon.
Use a recent 5K or 10K result to estimate your half marathon or marathon time with the Riegel formula.
Enter your progress so far to see a projected finish time and remaining pace requirement.
Feed checkpoint distances and times into the Multipoint tool to see exactly where your pace changed.
Convert a treadmill's mph or km/h display into a familiar outdoor race pace using the Converter tab.
Switch between metric and imperial when training or racing in a country that uses a different unit system.
Coaches can quickly generate target splits and predicted times for multiple athletes at once.
Use the splits table to plan a steady, even-effort pace rather than starting too fast and fading.
Convert a target pace into per-km or per-mile split times for structured track and tempo sessions.
Use the Converter and Riegel predictions to compare a 5K time fairly against a 10K or half marathon result.
Verify your device's reported pace or speed against a manually calculated value from distance and time.
Use the Converter's mph/km/h units for cycling legs of a triathlon or general endurance training.
Illustrate pace, speed, and Riegel-formula race prediction concepts for students or new runners.
What this pace calculator does well, and where it can't replace real-world testing
Common training paces converted across all four core units
| Pace (/km) | Pace (/mi) | Speed (km/h) | Speed (mph) |
|---|---|---|---|
| 4:00 /km | 6:26 /mi | 15.00 km/h | 9.32 mph |
| 4:30 /km | 7:15 /mi | 13.33 km/h | 8.28 mph |
| 5:00 /km | 8:03 /mi | 12.00 km/h | 7.46 mph |
| 5:30 /km | 8:51 /mi | 10.91 km/h | 6.78 mph |
| 6:00 /km | 9:39 /mi | 10.00 km/h | 6.21 mph |
| 6:30 /km | 10:28 /mi | 9.23 km/h | 5.74 mph |
| 7:00 /km | 11:16 /mi | 8.57 km/h | 5.33 mph |
Summary: This pace calculator gives you an instant, free way to solve for pace, time, or distance, break a race into checkpoint splits, convert between 8 pace and speed units, and project a mid-race finish time — a practical running pace calculator for training and race day alike, not a substitute for a full training plan. Pair it with related tools like the Target Heart Rate Calculator and TDEE Calculator for a fuller picture of your training and energy needs.
Common questions about pace calculations
Official guidance to complement this calculator — not a substitute for licensed medical or coaching advice
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