Running Pace: How to Calculate It and Use Training Zones

Understanding Pace

Pace = time per unit distance (min/mile or min/km). It's the inverse of speed.

• Pace = Total time ÷ Distance
• Finish time = Pace × Distance
• Speed (mph) = 60 ÷ Pace (min/mile)

Common Race Distance Reference Paces

• 5K: 30 min = 9:41/mi | 25 min = 8:03/mi | 20 min = 6:26/mi
• Half marathon: 2:00 = 9:09/mi | 1:45 = 8:00/mi | 1:30 = 6:51/mi
• Marathon: 4:00 = 9:09/mi | 3:30 = 8:00/mi | 3:00 = 6:51/mi

Training Pace Zones

• Easy run (60–70% HR): 90+ sec/mile slower than race pace — conversational
• Tempo run (75–85% HR): "Comfortably hard," 30–40 sec/mile slower than 5K pace
• Interval (90–100% HR): Near 5K race pace or faster, short repeats

The most common mistake: all runs at the same moderate pace. Easy should be truly easy; hard should be hard.

Predicting Race Times

Riegel's formula: T2 = T1 × (D2/D1)^1.06. Example: 5K in 25 min → predicted 10K = 25 × (6.2/3.1)^1.06 = 52 min.