Running Pace Calculator

Running pace = Total Time ÷ Distance. For example, if you run 5K in 25 minutes, your pace is 25 ÷ 5 = 5:00 per kilometer (or 8:02 per mile). Our calculator does this automatically—just enter your distance and time, and it calculates your pace in min/km or min/mile, plus your speed in km/h, mph, and m/s.

For beginners, a conversational pace (you can talk while running) is ideal. This is typically 6:30-8:00 min/km (10:30-13:00 min/mile). Don't worry about speed—focus on completing the distance comfortably. As your fitness improves, your pace will naturally get faster. Most beginners finish their first 5K in 30-40 minutes.

Training zones are intensity levels based on your pace or heart rate. They help you train effectively: EASY/RECOVERY (slowest) builds aerobic base without fatigue. AEROBIC develops endurance. TEMPO builds lactate threshold. THRESHOLD is race-pace effort. INTERVAL develops VO2max. REPETITION (fastest) improves running economy. Training at the right mix of zones prevents overtraining and optimizes performance gains.

Our race predictor uses the Riegel formula: T2 = T1 × (D2/D1)^1.06. It predicts your time for one distance based on your performance at another. For example, a 25-minute 5K predicts roughly a 52-minute 10K and a 1:55 half marathon. The formula accounts for the fact that you can't maintain the same pace over longer distances—you naturally slow down.

Race predictions are estimates, not guarantees. Accuracy depends on: (1) Similar training—predictions assume you've trained appropriately for the longer distance. (2) Similar conditions—terrain, weather, and elevation affect results. (3) Race experience—newer runners may outperform predictions as they learn pacing. Predictions work best when comparing similar distances (5K to 10K is more accurate than 5K to marathon).

Pace bands show your finish time at different paces (+/- seconds from your target). They help you: (1) Plan race strategy—know how a few seconds per km affects your finish. (2) Adjust during the race—if you're ahead/behind pace, see your projected finish. (3) Set realistic goals—see the range of possible outcomes. Even 5 seconds per km adds up over a marathon (3+ minutes).

To PR a 5K, you'll run near your threshold pace (the fastest pace you can sustain for 20-30 minutes). It should feel 'comfortably hard'—you can speak only a few words at a time. For a 25-minute 5K goal, target 5:00/km pace. For 20 minutes, target 4:00/km. Start slightly conservative and negative split (run the second half faster) for best results.

1 kilometer = 0.621 miles. 1 mile = 1.609 km. For pace: multiply min/km by 1.609 to get min/mile. For example, 5:00/km = 8:02/mile. Quick mental math: add 60% to min/km to estimate min/mile (5:00 + 3:00 ≈ 8:00). Our calculator toggles between units automatically.

Negative splitting means running the second half of a race faster than the first. It's considered optimal race strategy: you start conservatively when fresh and finish strong when others are fading. For example, in a marathon, running the first half in 1:35 and second half in 1:30 is a negative split. It requires discipline but leads to faster overall times and better race experiences.

For first-time marathoners, focus on finishing, not time. A common approach is to run 1-2 minutes per km slower than your 10K pace. If you run 10K in 55 minutes (5:30/km), target 6:30-7:00/km for the marathon (4:30-5:00 finish). Most first-timers finish between 4-5 hours. Walk breaks (run/walk method) are perfectly acceptable and often lead to faster finishes than going out too fast.

To get faster: (1) RUN MORE—increase weekly mileage gradually (max 10%/week). (2) RUN EASY MOST OF THE TIME—80% of runs should be easy. (3) ADD SPEEDWORK—weekly intervals or tempo runs. (4) STAY CONSISTENT—months and years of training compound. (5) RECOVER—rest, sleep, and nutrition matter. (6) STRENGTH TRAIN—builds running economy. (7) BE PATIENT—sustainable improvement takes time.

Threshold pace (also called lactate threshold or tempo pace) is the fastest pace you can sustain for about 60 minutes in a race. It's roughly your 10K-15K race pace or 10-mile pace. At this intensity, your body is at the boundary between aerobic and anaerobic energy systems. Training at threshold improves your ability to run faster before fatigue sets in.

No. Effective training varies intensity across days. Easy recovery runs (very slow) allow adaptation from hard efforts. Long runs build endurance at moderate pace. Speed sessions (intervals, tempo) build fitness at faster paces. The mixture—not just one pace—creates balanced improvement. Running the same moderate pace every day limits progress and increases injury risk.

Many factors affect pace: (1) TERRAIN—hills, trails, sand slow you down. (2) WEATHER—heat, humidity, wind, cold affect performance. (3) ALTITUDE—higher elevation = slower pace. (4) FATIGUE—after hard training or poor sleep. (5) FUELING—dehydration and glycogen depletion hurt pace. (6) MENTAL STATE—stress and motivation matter. (7) TIME OF DAY—most run fastest in late afternoon. Some days are just harder than others.

No. This calculator runs entirely in your browser. Your running data is processed locally on your device and is never sent to our servers or stored anywhere. When you close the page, all data is cleared. Your training information stays private.