Running Pace Calculator
Calculate running pace, finish time, or distance from any two of the three — with race-time projections for 5K, 10K, half marathon, and marathon.
That's a pace of 3:06/km (5:00/mi) at an average speed of 19.31 km/h (12.00 mph).
Race times at this pace
Results update as you type. Race projections assume even pace — real race times typically slow slightly over longer distances due to fatigue and hills.
Formula
Three identities: pace = time / distance,
time = pace × distance, and
distance = time / pace. The race
projections multiply your pace per kilometer by the four standard distances (5 km, 10 km,
21.0975 km, 42.195 km).
When to use this calculator
American runners overwhelmingly think in minutes per mile, and this calculator is built around that while still showing the per-kilometer figure that 5K and 10K race distances are named for. Reach for it when you have just logged a run and want your pace, when you are chasing a goal time for a road race or a fall marathon, or when you have only two of the three numbers — pace, time and distance — and need the calculator to solve for the third.
It answers the questions runners actually ask: what pace do I need to break 50 minutes in a 10K, if I run 9 minutes per mile how long does a half marathon take, what does my plan's prescribed 'easy 6 miles' come out to in time. Because the result shows pace in both miles and kilometers, you can line it up with a race that lists distance in kilometers while you train and plan in miles.
Reading your result
Pace is the main number: minutes per mile, the unit nearly every US training plan, treadmill and race clock uses. The finish-time projection multiplies that pace across the race distance, so holding 9:00 per mile over 26.2 miles projects to about 3 hours 56 minutes. The longer the race, the more a small pace change moves the finish, which is why marathon goals are so sensitive to your per-mile target.
Read the projection as a target ceiling, not a promise. It assumes an even effort the whole way, and real races rarely cooperate — expect to come in a couple of percent slower for a 10K and below, and meaningfully slower over the half and full marathon, once pace fade, hills and aid stations are factored in. The number is best used to set the splits you will try to hold.
A worked example
Say you run a 5K in 24 minutes. That works out to a pace of about 7:44 per mile, or 4:48 per kilometer. Carry a slightly easier 8:15 per mile to a 10-miler and the projection is roughly 1 hour 23 minutes. Step up to a half marathon at 8:30 per mile and you are looking at about 1 hour 51 minutes. If you ever need the metric equivalent for an internationally timed race, 8:30 per mile is close to 5:17 per kilometer — the calculator shows both so you never have to stop and convert.
Mistakes to watch for
Most projections that disappoint come from going out too hard or misreading what the arithmetic assumes.
- Starting faster than goal pace and fading in the back half — the projection assumes the steady pace you actually have to run.
- Forgetting that a 5K or 10K is named in kilometers while you train in miles, so double-check which unit a result is in.
- Ignoring summer heat and humidity, hills and crowded race starts, all of which cost time the calculator never sees.
- Treating marathon pace as just your 10K pace held longer — endurance fades faster than the distance grows.
Pacing for US road races
American distance running is built on a huge road-race calendar, from neighborhood 5Ks and turkey trots to the marquee marathons in Boston, New York and Chicago. Boston is the one most runners measure themselves against because it requires a qualifying time, so a precise goal pace genuinely matters — your projected finish has to clear a published standard for your age and gender. That makes a reliable pace target more than a nicety.
A practical approach is to take a recent shorter race, set your per-mile pace from it, then project the longer distance while trimming a little for fatigue. Keep the calculator on miles for day-to-day planning, but glance at the per-kilometer figure when a race or an international plan is written in metric, so your splits always match the clock you will be running against.
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Frequently asked questions
What's a typical running pace?▾
Wide range. New runners often start around 12:00–14:00 per mile (~7:30–8:45 per km). Recreational runners settle around 9:00–11:00/mi (~5:35–6:50/km). Sub-3-hour marathoners run ~6:50/mi (~4:15/km). Elite men's marathon record is ~4:35/mi (2:50/km). Compare yourself to your own past times rather than averages — pace is profoundly individual.
What's the math?▾
Pace = time ÷ distance. 5 miles in 50 minutes = 10 min/mile. Time = pace × distance. Distance = time ÷ pace. The calculator above does whichever direction you need based on which two fields you fill in.
How do I project a marathon time from a 5K?▾
Several formulas exist; the simplest is the Riegel formula: T2 = T1 × (D2 / D1)^1.06. So a 22-minute 5K projects to a 22 × (26.2/3.1)^1.06 ≈ 3h26 marathon — under perfect conditions. Real marathons usually run ~5–10% slower than the formula because endurance fades faster than the exponent assumes. This calculator just multiplies pace by distance, which assumes even effort throughout.
Pace per km vs pace per mile?▾
American races and treadmills usually report pace per mile; international races and most fitness apps default to per kilometer. The result above shows both. Conversion: minutes per mile × 0.6214 = minutes per km. 8:00/mi = 4:58/km, 10:00/mi = 6:13/km, 12:00/mi = 7:27/km.
Why don't real-world race times match this calculator?▾
Three reasons. First, pace fade: most runners slow over the second half. Second, course terrain — hills, wind, aid stations cost time. Third, race-day variables (heat, humidity, GI distress, crowded starts). The calculator is pure arithmetic — useful for setting target paces, but real finish times are typically 2–5% slower for 10K and below, 5–10% slower for half/full marathon.
Should I train at race pace?▾
Mostly no. Established training plans (Daniels, Pfitzinger, Hansons, Hal Higdon) prescribe most runs at much slower paces than goal race pace, with smaller doses of tempo, interval, and at-pace work. Spending all training at race pace plateaus and injures you. Pace targets are useful for race day planning, not weekly training.