NumberTally Pace Calculator
Enter any two of distance, time, and pace to find the third — in kilometers or miles. Get per-km splits, finish-time predictions for standard race distances, and compare your pace against a goal pace.
Advanced options
Compare your finish time against this pace over the distance above.
Your best recent race at that distance.
Pace, speed, and distance — the triangle
Pace is time per unit of distance (minutes per kilometer); speed is distance per unit of time (kilometers per hour). They describe the same effort from opposite directions: speed in km/h equals 60 divided by pace in minutes per km, so a 5:00/km pace is exactly 12.0 km/h. Given any two of distance, time, and pace, the third follows with no rounding beyond the displayed digits.
To convert pace between units, multiply a per-km pace by 1.60934 to get per-mile (5:00/km → 8:03/mi), or divide a per-mile pace by 1.60934 to get per-km. The unit selector above handles this automatically.
Using splits and predictions on race day
Even splits — running each kilometer at nearly the same pace — usually produce the fastest overall time, because going out too fast is the classic reason for fading late. Check the splits table below before a race and pick a target pace you can hold to the finish. The finish-time predictor applies your current pace to 5K, 10K, half marathon, and marathon distances; treat longer predictions as optimistic, since fatigue slows most runners over longer races.
Frequently Asked Questions
What is a good 5K pace for a beginner?
There is no single number that counts as good — it depends on age, training history, and goals. Track your own trend instead: run the same distance under similar conditions and watch your pace improve over weeks of consistent training.
How do I convert pace from min/km to min/mi?
Multiply by 1.60934, because one mile equals 1.60934 kilometers. A 5:00/km pace is 300 seconds per km, and 300 × 1.60934 = 482.8 seconds per mile — 8:03/mi. The unit selector above does this conversion automatically.
What is the difference between pace and speed?
Pace is time per unit of distance (5:00 per kilometer). Speed is distance per unit of time (12.0 km/h). Convert with: speed in km/h = 60 ÷ pace in minutes per km.
Why is my race pace slower than my training pace?
Hills, wind, heat, altitude, crowded starts, and going out too fast all slow you down versus a flat training route. Pacing even splits usually produces the fastest overall time — use the splits table to set a realistic target.
How accurate is the pace math?
The arithmetic is exact. Real-world differences come from measurement, not math — GPS watches can mismeasure distance under tree cover or near tall buildings. Treat watch pace as a guide and perceived effort as the backup.
Estimates only — not medical advice. Build up training gradually.