All tools
41 running calculators. Live results, no signup.
Pace & Race
Pace, splits, predictions, qualifying.
- Pace calculatorEnter any two of time, distance, and pace. Get min/mile, min/km, speed, even-pace finish times, and splits.
- Race time predictorEstimate another distance from a recent race using the Riegel fatigue model — not even pace.
- Pace converterConvert min/mile, min/km, mph, and km/h.
- Split calculatorPrint mile, km, or 400m splits for any distance.
- Pace bandPrintable wrist-strip split band. Marathon 4:00 Even is 9:09/mi · 5:41/km.
- Pace cardGoal time to a watch-face card with pace and key splits. Save as PNG or share a link. Marathon 4:00:00 is 9:09/mi · 5:41/km.
- BQOfficial B.A.A. 2026/2027 qualifying standard vs a marathon finish. Men 40 in 3:00:00 is 5:00 under 3:05:00.
- Age gradeWMA 2025 road age-grade % for 5K through marathon. Male 40 in 3:30 is 58.7%.
- Track pacePace or goal race time to 400 m lap times, 100–1600 m splits, and lane 1–8 lap times. 8:00/mi is a 1:59.3 lap · 4:58/km.
Race distances
Goal time to pace for every distance.
Training
Zones, fitness tests, cadence, treadmill.
- Heart rate zonesFive ACSM-style zones from age. Tanaka HRmax, optional Karvonen. Not medical advice.
- Critical speedHughson–Jones CS and D′ from two all-out races. 5K in 25:00 and 10K in 52:00 is 8:41/mi.
- Cooper testDistance covered in a 12-minute run to estimated VO2max (Cooper 1968), average pace per mile and km, and an age/sex fitness rating. 1.5 mi is 42.7 ml/kg/min.
- CadenceSPM and stride length from pace. 9:27/mi at 170 SPM is ~1.00 m step.
- Treadmill paceTreadmill mph and km/h to min/mile and min/km, with ACSM incline. 0% matches the pace converter.
- Run/walkRun pace, walk pace, and a Galloway-style run/walk ratio to average pace, finish time, % running, and walk breaks. 4:00/1:00 at 9:00/mi is 9:47/mi.
Conditions
Heat, altitude, wind, and hills.
- Heat paceCool-weather pace plus dew-point seconds per mile. 7:00/mi at 70°F is 7:48/mi.
- Altitude paceSea-level pace plus elevation seconds per mile. 7:00/mi at 5000 ft is 7:30/mi.
- Wind paceStill-air pace and wind speed to equal-effort pace in a headwind, tailwind, crosswind, or out-and-back. 8:00/mi into 10 mph is 8:17/mi.
- GAPTurn a hill pace into the flat-equivalent GAP from grade %. 9:27/mi at +5% is 7:16/mi.
Fuel & Body
Gels, fluids, and calories.
- Fueling / gelsCarbs per hour and gels to carry from finish time. Timed fuel band. Not medical advice.
- Sweat ratePre- and post-run weight, fluid drunk, and run time to sweat rate, % body weight lost, and a drink-every-15-minutes plan. 160→158 lb + 16 fl oz in 1:00 is 46.7 fl oz/hr.
- Calories burnedMET estimate from time, distance, and body weight. Not medical advice.