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.

Pace Calculation Formulas

Race Pace Reference Tables

Worked Examples

How to Use the Pace Calculator

Frequently Asked Questions

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