Pace Calculator
Calculate pace, finish time, or distance — with splits, race predictions, and training zones
Enter distance or select a race preset below
Enter your target pace per kilometer or mile
Used only for calorie burn estimation
Enter Your Numbers
Fill in any two fields and the third will be calculated automatically. Use the presets for standard race distances.
Important
This calculator is provided for general information only and is not medical advice, diagnosis, or treatment. Results are estimates based on population averages and cannot account for your individual circumstances. Speak to a qualified healthcare professional before acting on anything you read here.
Calculate pace, finish time, or distance — with splits, race predictions, and training zones
Welcome to the most comprehensive free running pace calculator online. Whether you are a first-time 5K runner working toward your debut or an experienced marathoner dialing in your negative-split strategy, this tool covers every aspect of pace planning you need — all running directly in your browser with no signup required. At its core, a pace calculator answers the fundamental question every runner faces: given two of the three variables — distance, time, and pace — calculate the third. Run a 5K in 28:30? What was your per-kilometer pace? Targeting a 3:45 marathon? What pace per mile is that? Need to cover exactly 8 kilometers in under 45 minutes? What pace do you need to hold? Our three-mode solver answers all three scenarios instantly. Pace is typically expressed in minutes per kilometer or minutes per mile. These are the standard formats used by GPS watches, race timing mats, and training logs worldwide. The conversion between the two is straightforward: one mile equals 1.60934 kilometers, so a pace of 5:00 per kilometer equals approximately 8:03 per mile. Both are shown simultaneously in our results so you never have to convert manually. Beyond simple pace, finish time, and distance, this calculator provides several layers of analysis that help runners plan smarter training and race strategies. The split table feature generates per-kilometer or per-mile intermediate splits from your target pace and distance. Splits are the building blocks of race execution — knowing what the clock should read at the 10K mark of a marathon tells you whether you are on track or drifting off pace. You can generate even splits, where every segment is run at the same pace, or apply a split strategy. Negative splits mean running the first half slightly slower (5% above target pace) and the second half slightly faster (5% below target pace). This strategy is backed by exercise physiology research and used by most world record holders. Positive splits do the opposite, starting fast and finishing slower, a common unintentional pattern for runners who go out too hard. The race equivalency predictor uses Riegel's formula — T2 = T1 × (D2 ÷ D1)^1.06 — to estimate how your recent performance at one distance translates to a predicted finish time at other distances. If you ran a 10K in 48:00 last weekend, the calculator can predict your likely marathon finish time based on that performance. This formula is the industry standard used by major coaching tools and has been empirically validated against thousands of race results. Note that the formula assumes equal training and conditions and tends to slightly underestimate performance for runners who are specifically trained for longer or shorter events. Pace zone classification places your pace on a spectrum from Beginner through Elite based on peer-reviewed pace benchmarks. The five zones — Beginner (above 6:00/km), Novice (5:00–6:00/km), Intermediate (4:00–5:00/km), Advanced (3:30–4:00/km), and Elite (below 3:30/km) — give meaningful context to your numbers. A visual horizontal bar shows exactly where your pace falls across the full spectrum. Training zone paces translate your current fitness level into specific pace targets for different workout types. Based on Jack Daniels' VDOT methodology, the five zones are Easy (long run pace, promotes aerobic base), Marathon Pace (goal marathon effort), Threshold (comfortably hard, improves lactate threshold), Interval (approximately 5K race effort, improves VO2 max), and Repetition (fast short repeats, improves running economy). These zones are calculated relative to your 5K equivalent pace so they update automatically as you change your inputs. The pace band table shows the impact of running slightly faster or slower than your target pace across six variations (±5, ±10, ±15 seconds per kilometer or mile). This is invaluable for pre-race planning because it answers the question: if I run just 10 seconds per kilometer faster than planned, how much time do I gain over the marathon? The answer for a typical marathon runner is often more than seven minutes — a powerful reminder of why pacing discipline matters. Calorie burn estimation uses the metabolic equivalents formula with your weight and pace to give a rough estimate of energy expenditure. Running is one of the highest-calorie-per-hour activities, and understanding energy cost helps with race nutrition planning — particularly for events over 90 minutes where glycogen depletion becomes a factor. All calculations happen instantly as you type, with no page reloads and no data sent to any server. Results can be copied to clipboard in a clean format suitable for printing as a race-day pacing band. Use the standard race presets (5K, 10K, Half Marathon, Marathon) to fill in the distance field instantly, or enter any custom distance for training runs and ultras.
Understanding Pace Calculations
Pace, time, and distance are three sides of the same equation. Understanding how they relate — and how to use advanced metrics like race prediction and training zones — turns numbers into actionable race plans.
The Pace-Time-Distance Triangle
The three core variables in running — pace, time, and distance — are directly related: Pace = Time ÷ Distance, Time = Pace × Distance, Distance = Time ÷ Pace. Pace is expressed in minutes per unit (per kilometer or per mile). Speed is the reciprocal: Speed (km/h) = 60 ÷ Pace (min/km). A pace of 6:00/km equals a speed of 10 km/h. A pace of 5:00/mile equals a speed of 12 mph. Switching between pace and speed is a matter of taking the reciprocal and multiplying by 60. Our calculator handles all these conversions automatically, showing both min/km and min/mile pace alongside km/h and mph speed in every result.
Split Strategies and Race Execution
A split is your time for a segment of a race, typically per kilometer or per mile. Even splits mean every segment is run at an identical pace, producing the most efficient biomechanical output. Negative splits — where the second half of a race is run faster than the first — are associated with the vast majority of world records and personal bests. The physiological reason is that starting conservatively preserves glycogen and avoids early lactic acid accumulation, leaving energy available to accelerate in the final miles. Positive splits, starting fast and fading, are the most common unintentional race pattern among runners who underestimate the later stages of a race.
Riegel Race Prediction Formula
The Riegel formula (T2 = T1 × (D2/D1)^1.06) is the most widely used and empirically validated race equivalency predictor. The exponent 1.06 captures the fact that fatigue accumulates super-linearly with distance — you cannot simply scale your 5K pace linearly to predict a marathon because the marathon is physiologically far harder per unit distance. The formula was derived from analysis of thousands of race performances and has been validated independently multiple times. It works best when the two distances being compared are within a factor of 10 of each other. It assumes equal preparation, conditions, and course profile for both races.
Pace Zone Classification
Pace zones classify a runner's pace into performance tiers based on data from large populations of recreational and competitive runners. Elite runners (below 3:30/km or 5:38/mile) represent the top fraction of a percent of all runners. Advanced runners (3:30–4:00/km) compete regularly and have multiple years of structured training. Intermediate runners (4:00–5:00/km) are experienced recreational runners who train consistently. Novice runners (5:00–6:00/km) are newer to distance running or focused primarily on completing their events. Beginners (above 6:00/km) are newer runners building their base fitness. These zones provide context for your current performance and benchmarks to aim for as you improve.
Pace Calculation Formulas
Pace from Time and Distance
Pace = Time ÷ Distance
The fundamental pace formula. Divide your total time (in minutes) by your distance to get minutes per kilometer or minutes per mile.
Speed from Pace
Speed (km/h) = 60 ÷ Pace (min/km)
Convert pace to speed by dividing 60 by your pace in minutes per unit. A pace of 5:00/km equals a speed of 12 km/h.
Finish Time from Pace and Distance
Finish Time = Pace × Distance
Multiply your target pace by the race distance to predict your finish time. For example, a 5:30/km pace over 10 km gives a 55:00 finish time.
Pace Conversion (km ↔ mi)
Pace (min/mi) = Pace (min/km) × 1.60934
Convert between metric and imperial pace by multiplying or dividing by the kilometer-to-mile factor of 1.60934.
Race Pace Reference Tables
Race Paces for Common Finish Times
Target pace per kilometer and per mile for popular finish times across four standard race distances.
| Race | Finish Time | Pace (min/km) | Pace (min/mi) | Speed (km/h) |
|---|---|---|---|---|
| 5K | 20:00 | 4:00 | 6:26 | 15.0 |
| 5K | 25:00 | 5:00 | 8:03 | 12.0 |
| 5K | 30:00 | 6:00 | 9:39 | 10.0 |
| 10K | 40:00 | 4:00 | 6:26 | 15.0 |
| 10K | 50:00 | 5:00 | 8:03 | 12.0 |
| 10K | 60:00 | 6:00 | 9:39 | 10.0 |
| Half Marathon | 1:30:00 | 4:16 | 6:52 | 14.1 |
| Half Marathon | 2:00:00 | 5:41 | 9:09 | 10.6 |
| Half Marathon | 2:30:00 | 7:06 | 11:27 | 8.4 |
| Marathon | 3:00:00 | 4:16 | 6:52 | 14.1 |
| Marathon | 3:30:00 | 4:59 | 8:01 | 12.1 |
| Marathon | 4:00:00 | 5:41 | 9:09 | 10.6 |
| Marathon | 4:30:00 | 6:24 | 10:18 | 9.4 |
| Marathon | 5:00:00 | 7:06 | 11:27 | 8.4 |
Worked Examples
Calculate Pace for a 5K in 25 Minutes
A runner finishes a 5K race in 25 minutes and wants to know their pace per kilometer and per mile.
Distance = 5 km, Time = 25:00
Pace (min/km) = 25 ÷ 5 = 5:00/km
Pace (min/mi) = 5:00 × 1.60934 = 8:03/mi
Speed = 60 ÷ 5.0 = 12.0 km/h (7.46 mph)
The runner's pace is 5:00 per kilometer (8:03 per mile), which places them in the Intermediate pace zone at a speed of 12 km/h.
Predict Marathon Time from 10K Pace
A runner completed a 10K in 50 minutes and wants to predict their marathon finish time using Riegel's formula.
10K time (T1) = 50 minutes, 10K distance (D1) = 10 km
Marathon distance (D2) = 42.195 km
Riegel formula: T2 = T1 × (D2 ÷ D1)^1.06
T2 = 50 × (42.195 ÷ 10)^1.06 = 50 × 4.2195^1.06
T2 = 50 × 4.534 = 226.7 minutes ≈ 3:46:42
Based on their 50-minute 10K, the predicted marathon finish time is approximately 3:46:42, requiring a pace of about 5:22/km (8:39/mi).
Plan Negative Splits for a Half Marathon
A runner targeting a 2:00:00 half marathon wants to plan negative splits with a 5% differential.
Target pace = 5:41/km, Total distance = 21.0975 km
First half pace (+5%): 5:41 × 1.05 = 5:58/km
Second half pace (-5%): 5:41 × 0.95 = 5:24/km
First 10.5 km time: 10.5 × 5.97 = 62:41
Second 10.6 km time: 10.6 × 5.40 = 57:14
Run the first half at 5:58/km and accelerate to 5:24/km for the second half. This negative split approach conserves glycogen early and enables a strong finish.
How to Use the Pace Calculator
Choose What to Calculate
Select your solve mode at the top: Pace (calculate your pace from distance and time), Finish Time (calculate how long a race will take at your target pace), or Distance (calculate how far you can run in a given time at a given pace). The two input fields you fill in will determine the third automatically.
Enter Distance and Use Presets
Type any custom distance or click one of the race presets — 5K, 10K, Half Marathon, Marathon, 50K, or 100K — to fill the distance field instantly. Choose your unit system (metric or imperial) to work in kilometers or miles. The pace and results will display in your selected unit system throughout.
Review Your Split Table
Once results appear, scroll to the Split Table section. Choose your split interval (every km or every mile) and select a split strategy — Even for consistent pacing, Negative for a faster second half, or Positive for a faster first half. The table shows your target pace and cumulative time at each split point. Use the Copy Splits button to copy the table to your clipboard for printing as a race-day pacing band.
Explore Race Predictions and Training Zones
The Race Predictions section uses Riegel's formula to estimate your finish times at four standard distances based on your current pace. The Training Zones section shows target pace ranges for five workout types (Easy, Marathon, Threshold, Interval, Repetition) derived from your current fitness. The Pace Band table shows how ±5, ±10, and ±15 second pace variations affect your total finish time.
Frequently Asked Questions
What is running pace and how is it different from speed?
Running pace is the time it takes to cover one unit of distance, expressed in minutes per kilometer (min/km) or minutes per mile (min/mile). Speed is the inverse: distance covered per unit of time, expressed in kilometers per hour (km/h) or miles per hour (mph). To convert pace to speed, divide 60 by your pace in minutes: a pace of 5:00/km gives a speed of 60 ÷ 5 = 12 km/h. To convert speed to pace, divide 60 by your speed: 10 km/h gives a pace of 60 ÷ 10 = 6:00/km. Runners typically use pace because it scales directly to distance targets, making it easier to plan splits and check progress mid-race. Speed is more commonly used on treadmills and by cyclists.
How accurate is the Riegel race predictor?
Riegel's formula (T2 = T1 × (D2/D1)^1.06) is highly accurate when comparing performances at similar distances — for example, predicting a 10K time from a recent 5K performance. Accuracy decreases when predicting across very different distances, such as predicting a marathon from a mile time, because training specificity and physiology differ dramatically between short and long events. The formula also assumes equal fitness, equal training for the target distance, similar course profiles, and similar environmental conditions. Runners who are specifically trained for longer events often outperform the formula's predictions, while untrained runners attempting their first marathon may underperform. Use the predictions as planning benchmarks, not guarantees.
What is a negative split and why is it recommended?
A negative split means running the second half of a race faster than the first half. This is the opposite of what most untrained runners do — most recreational runners go out too fast, deplete glycogen early, and slow down significantly in the final miles. Negative splits work because starting conservatively preserves muscle glycogen, avoids early lactic acid accumulation, and keeps your heart rate and body temperature in a manageable zone. The physiological and biomechanical state at mile 20 of a marathon depends heavily on how controlled you were in miles 1 through 13. This calculator's negative split strategy sets the first half at 5% above your average target pace and the second half at 5% below, which is a mild differential suitable for most runners.
What do the pace zones mean?
Pace zones classify your running pace relative to the wider population of recreational and competitive runners. Elite runners (below 3:30/km or 5:38/mile) represent Olympic-level or sub-elite competitive runners. Advanced runners (3:30–4:00/km or 5:38–6:26/mile) are experienced club runners who compete seriously. Intermediate runners (4:00–5:00/km or 6:26–8:03/mile) are regular runners with consistent training and race experience. Novice runners (5:00–6:00/km or 8:03–9:39/mile) are newer to running or focusing on completing events rather than competing. Beginners (above 6:00/km or 9:39/mile) are building their base fitness. These zones provide context for your pace and a framework for setting progression goals.
How do training zones work?
Training zones are pace ranges associated with different physiological adaptations. Easy pace (approximately 25% slower than 5K pace) is used for long runs and recovery runs; it builds aerobic base and improves fat utilization without excessive stress. Marathon pace is your target race effort for the marathon event. Threshold pace (approximately 8% slower than 5K pace) is used for tempo runs of 20 to 40 minutes and improves your lactate threshold, the key predictor of distance running performance. Interval pace (approximately 5K race pace) is used for track repeats of 800m to 1600m and improves VO2 max. Repetition pace (approximately 5% faster than 5K pace) is used for short fast repeats and improves running economy and neuromuscular coordination.
How is the calorie estimate calculated?
The calorie estimate uses a simplified MET (Metabolic Equivalent of Task) approach: calories per minute = (MET × weight_kg × 3.5) / 200, multiplied by total minutes. The MET value for running varies with pace — slower running (above 6:00/km or 9:39/mile) has a MET of approximately 8, moderate running (5:00–6:00/km or 8:03–9:39/mile) uses a MET of 10, and fast running (below 5:00/km or 8:03/mile) uses a MET of 12 or higher. A rougher but commonly cited estimate is that running burns approximately 1 kcal per kilogram of body weight per kilometer, which this calculator also uses as a cross-check. Individual calorie expenditure varies based on running efficiency, body composition, terrain, and environmental conditions.
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