Running Pace Calculator
Choose a calculation at the top, enter distance, time, or pace on the left, and see pace, speed, and standard race projections together on the right.
Inputs
Results
Results use the values you enter. Race projections assume you hold the same pace for the entire distance.
ready to use.
- Visible firstKeep the input and result positions clear.
- Results firstPut the main number up front and keep the process secondary.
- Less to askNo sign-up or extra information before using the tool.
Turn a running time into a useful pace
A distance and a finish time tell you what happened. Pace and speed make that run easier to compare with a workout, a treadmill setting, or a race plan. In the US view, 9:00/mi and about 6.7 mph describe the same effort in two different formats.
This calculator analyzes a completed run, estimates finish time or distance, and converts pace and speed. It also extends the effective pace across standard race distances. Those projections are straight arithmetic, not a promise that a 5K pace will hold through a marathon.
Pace measures time per mile; speed measures miles per hour
Pace answers how long one mile takes. Speed answers how far you travel in one hour. Runners usually plan outdoor splits with pace, while treadmills commonly show speed.
A 9:00 mile equals 6.7 mph after rounding to one decimal. The calculator keeps both values tied to the same underlying speed.
- Pace works well for mile splits and race checkpoints.
- Speed matches most US treadmill controls.
- Elapsed time covers the whole run or the segment you choose to analyze.
Analyze a completed run from its full distance and time
Use Analyze a run when you have a watch, race, or route result. Enter the distance you actually covered, choose miles or kilometers, and add the total elapsed time.
The result is an overall average. Hills, stops, and fast or slow splits are all folded into total time divided by total distance.
- Choose Analyze a run.
- Enter the recorded distance and select mi or km.
- Enter hours, minutes, and seconds.
- Read average pace, speed, and constant-pace race projections.
Build a finish-time target from race distance and pace
If you know the pace you want to hold, Finish time multiplies that pace by your target distance. The US view takes target distance in miles and pace in minutes per mile.
A half marathon is about 13.1094 miles and a marathon is about 26.2188 miles. The projection assumes uninterrupted pacing, so add planned stops separately.
- Enter 3.1069 mi for an exact 5K.
- Enter 6.2137 mi for an exact 10K.
- Enter 13.1094 mi for a half marathon.
- Enter 26.2188 mi for a marathon.
Estimate how far a time-limited run can go
Distance mode works for a 30-minute easy run, a one-hour long run, or any workout where time is fixed first. Divide the available seconds by seconds per mile to estimate miles.
Decide whether paused time belongs in the workout before comparing results. Moving time and elapsed time answer different questions.
- Enter the planned running time.
- Enter the average min/mi pace.
- Read estimated miles to two decimal places.
- Record whether stops were included.
Match treadmill mph with outdoor min/mi pace
Pace converter switches between min/mi and mph. A treadmill at 6.0 mph is 10:00/mi; 7.5 mph is 8:00/mi; 8.6 mph is about 6:58/mi after the calculator floors fractional seconds.
The numbers match mathematically, but belt running and outdoor running do not recreate the same wind, grade, or surface. Use the conversion as a setting reference rather than an effort guarantee.
- Pace → speed converts minutes and seconds per mile to mph.
- Speed → pace converts mph to min/mi.
- A valid converted pace also updates the race projection rows.
Average pace is not the same as every split
Average pace uses total elapsed time divided by total distance. Individual splits can vary because of hills, turns, traffic, water stops, or a fast start.
This tool does not build a split table. To compare sections, analyze each section with its own distance and time instead of averaging displayed pace strings.
The engine converts to kilometers and seconds before displaying US units
Distance is normalized with the exact conversion 1 mi = 1.609344 km, and time is normalized to seconds. The formulas then solve pace, speed, finish time, or distance.
Displayed pace and time floor fractional seconds. Speed shows one decimal, and estimated distance shows two decimals using the en-US decimal point.
Check the arithmetic with four US running examples
These examples use the same units and rounding rules as the live result panel.
- 5.00 mi in 45:00 → 9:00/mi and 6.7 mph.
- 13.1094 mi at 9:00/mi → 1:57:59 after fractional seconds are floored.
- 1:00:00 at 10:00/mi → 6.00 mi.
- 7.5 mph → 8:00/mi.
Road, track, GPS, and treadmill distances come from different sources
A pace result is only as accurate as the distance entered. Certified race distance, GPS route distance, track lane and lap count, and treadmill display each have a different measurement basis.
GPS can drift near buildings, trees, and tight turns. When comparing runs, use the same distance source or note the difference.
- Road race: separate official course distance from watch distance.
- Track: confirm lane and lap count.
- Treadmill: use the machine distance and speed, then note that outdoor conditions differ.
Treat standard-race rows as constant-pace math, not a race prediction
The 5K, 10K, half-marathon, and marathon rows extend the current pace over each official distance. A short-run pace may not remain realistic as distance increases.
Before racing, check course elevation, weather, wind, aid stations, crowding, fueling, and current condition. Adjust the plan when those facts change.
- Confirm whether the input uses miles or kilometers.
- Use average pace, not a single fastest split.
- Decide whether stopped time is included.
- Review elevation, heat, wind, hydration, and fuel.
- Do not force a calculator pace when race-day conditions disagree.
Distance and unit references
World Athletics defines the half marathon as 21.0975 km and the marathon as 42.195 km. Mile input uses the exact NIST conversion 1 mi = 1.609344 km.
Running pace calculator FAQ
What is the difference between pace and speed?
Pace is time per mile, while speed is miles per hour. A 9:00/mi pace is about 6.7 mph.
What pace is 5 miles in 45 minutes?
Forty-five minutes is 2,700 seconds. Dividing by 5 miles gives 540 seconds per mile, or 9:00/mi and about 6.7 mph.
How long is a half marathon at 9:00 per mile?
Using the exact 21.0975 km distance, the calculator displays 1:57:59 after flooring fractional seconds.
How far can I run in one hour at 10:00 per mile?
One hour is 3,600 seconds. Dividing by 600 seconds per mile gives 6.00 miles.
What pace is 7.5 mph?
The calculation is 3,600÷7.5=480 seconds per mile, which is 8:00/mi.
Can I enter a distance in kilometers?
Yes. Analyze a run lets you choose km or mi. The en-US result still displays pace in min/mi and speed in mph.
Are the race projection times predictions?
No. They assume one constant pace. Elevation, weather, crowding, stops, fatigue, and fueling can change the actual result.
Why does average pace differ from my mile splits?
Average pace uses total time divided by total distance. Split distance, pauses, hills, turns, and GPS variation can make individual splits differ.