Running Pace Calculator

Pace, speed and splits for any distance and time.

Calculate running pace per kilometre and mile from distance and time, with speed, common race splits and equivalent finishing times.

Written and maintained by Mohit PatelLast checked August 4, 2026How we build these

Distance

Hours

Minutes

min

Seconds

Pace

5:00 /km

8:03 per mile

Speed12.0 km/h

Speed (mph)7.5 mph

Equivalent 5 km25:00

Equivalent marathon3:30:59

Equivalent times here hold your pace constant. Real races slow as distance grows, the race time predictor models that decay.

How the Running Pace Calculator works

Pace is time per unit distance, and it is the number runners actually plan around. This converts between pace, speed and finishing time, and shows what your target pace means at each of the standard race distances.

Also known as: pace per mile calculator · min per km pace · race pace calculator

Pace, speed and the arithmetic between them

Pace is time per unit distance, minutes per kilometre or per mile. Speed is distance per unit time. They are reciprocals and runners think almost entirely in pace.

Converting between metric and imperial trips people up because the reciprocal relationship is not intuitive. A 5:00 per kilometre pace is 8:03 per mile, not 8:00, and the discrepancy grows at slower paces.

Splitting a target time across a distance is the most common use: a four hour marathon is 5:41 per kilometre or 9:09 per mile, held for the entire distance, which is the part people underestimate.

Training paces

Easy running should be genuinely easy, conversational, typically 60% to 90% slower per kilometre than race pace depending on the distance. Most runners run their easy days too fast.

Tempo or threshold pace is roughly the pace sustainable for an hour of racing, which for most runners is close to their 10 mile to half marathon pace. It is the pace that develops the ability to clear lactate.

Interval pace, for repetitions of three to five minutes, sits near 5 kilometre race pace or slightly faster. Repetition pace, for shorter faster efforts, is faster still and targets running economy and neuromuscular qualities rather than aerobic ones.

Even splits and negative splits

Running the second half of a race faster than the first, a negative split, is how nearly every distance record has been set and how very few amateur races are run.

The physiology supports it: starting conservatively preserves glycogen and delays the accumulation of fatigue, and the time lost in the first half is usually recovered with interest.

The psychology works against it. Adrenaline and a crowded start make the opening kilometres feel easy at a pace that is not sustainable, and the cost is paid later. For a marathon in particular, going out two per cent too fast can cost several minutes at the end.

What changes pace on the day

Heat is the largest factor and it is underestimated. Performance degrades noticeably above about 15 degrees for a marathon, and the effect compounds with humidity because evaporative cooling becomes less effective.

Elevation costs time uphill and does not return it all downhill, so a hilly course is slower than a flat one of the same distance even where the net elevation change is zero.

Wind is asymmetric in the same way: a headwind costs more than a tailwind returns. Altitude reduces oxygen availability and affects longer events more than shorter ones. Each of these is a reason to run to effort rather than to a pace on the day.

Setting a realistic target

The most reliable predictor of a target time is a recent race at a shorter distance, converted using an equivalence table or formula rather than by hoping.

Riegel's formula is the common one: predicted time equals known time multiplied by the ratio of distances raised to the power 1.06. It works reasonably from 5 kilometres up to the half marathon and tends to be optimistic for the marathon.

The marathon is optimistic for a specific reason: it is limited by glycogen availability and by musculoskeletal durability as much as by aerobic fitness, and neither is captured by a shorter race. Marathon predictions from 10 kilometre times regularly overstate what is achievable by ten minutes or more.

Where to go next

The Running Pace question rarely arrives on its own. These are the ones that usually come with it:

Race Time Predictor — Predict a race time from a result at another distance.
Calories Burned Calculator — Energy cost of an activity from its MET value.
VO2 Max Calculator — Aerobic capacity estimated from resting heart rate or a race time.
BMI Calculator — Body mass index with category and healthy weight range.

Sources

ACSM, Guidelines for Exercise Testing and Prescription

Not medical advice. This calculator gives a general estimate, not medical advice. It cannot account for your individual health, medical history, or medication. Talk to a qualified healthcare professional before acting on any result.

Frequently asked questions

How do I calculate running pace?

Divide total time by distance. A 50-minute 10 km is 50 ÷ 10 = 5:00 per kilometre. To convert to miles, multiply the per-kilometre pace by 1.609.

What is a good running pace?

For recreational runners, roughly 6:00-7:00 per kilometre is a comfortable steady pace, and around 5:00 is a solid tempo. Context matters far more than any absolute figure: terrain, heat, altitude and how long you are holding it all move the number.

What is negative splitting?

Running the second half of a race faster than the first. It is the pattern behind most well-executed distance races and the majority of world records, because starting conservatively delays the point at which fatigue forces a slowdown.

How much slower is marathon pace than 10K pace?

Typically 45-75 seconds per kilometre slower for trained runners. The relationship follows a power law rather than anything linear, which is what race-time prediction formulas like Riegel's are modelling.