Speed Calculator for Distance, Time, Pace and Units
Calculate speed from distance and elapsed time, or rearrange the same relationship to find distance or travel time. A separate trip mode finds moving and elapsed average speed across several legs, including optional stopped time.
Online Speed Calculator
Choose what you want to find, enter non-negative scalar values with their units, then review conversions, pace and the exact formula steps.
10 kilometres travelled in 50 minutes.
Result Conversions
| Unit | Relationship | Result |
|---|---|---|
| Kilometres per hour | Primary result | 12 km/h |
Calculation Steps
- Convert distance to metres and time to seconds.
- Divide total distance by elapsed time.
- Convert the result to the selected speed unit and pace.
How to Use This Speed Calculator
- Choose a calculation method. Find speed, distance, time or a whole-trip average across up to four legs.
- Enter the known values. Use total path distance for a speed problem. Enter elapsed time rather than a clock reading.
- Select every unit. The calculator converts distance to metres, time to seconds and speed to metres per second internally.
- Use clock formats carefully. Select h:mm:ss before entering a value such as 1:15:30. Select a pace unit before entering 5:30.
- Choose displayed precision. Four to ten significant digits change only the shown result, not the internal calculation.
- Calculate and review. Check the primary answer, conversions, pace, normalized duration and formula substitution.
- Check the model. A whole-trip result is average speed. It does not describe every instant or include direction.
All calculations stay in your browser. The page does not test vehicle speed, track your location or measure a network connection. It works only with the values you enter.
What Is Speed?
Speed describes how fast distance is covered. It is a scalar quantity, so it has magnitude but no direction. Average speed equals total distance travelled divided by total elapsed time. The SI expression for speed is metres per second, written m/s, although road travel often uses kilometres per hour or miles per hour.
If an athlete covers 10 kilometres in 50 minutes, convert 50 minutes to 5/6 hour. Dividing 10 km by 5/6 hour gives 12 km/h. The same motion equals 3.33333 m/s and a pace of 5:00 per kilometre.
Speed and velocity are different in physics. Velocity uses signed displacement and direction. A person who travels 3 km away from home and 3 km back covers 6 km, so average speed is positive. Net displacement is zero, so average velocity is zero. This calculator uses distance and speed only. It rejects negative scalar inputs rather than silently treating them as direction.
The definitions follow OpenStax Physics, Speed and Velocity.
Speed, Distance and Time Formulas
| Find | Formula | Required condition |
|---|---|---|
| Speed | v = d / t | Elapsed time must be greater than zero. |
| Distance | d = v × t | Speed and elapsed time must be non-negative. |
| Time | t = d / v | Speed must be greater than zero. |
| Pace | p = t / d | Speed and distance must be greater than zero. |
The letters are v for speed, d for distance and t for time. Units must agree before applying a formula. Multiplying 60 mph by 30 minutes directly gives a mismatched number. Convert 30 minutes to 0.5 hour first, then 60 mi/h × 0.5 h = 30 miles.
For pace, this calculator supports decimal minutes and clock-style minutes:seconds. A pace of 5:30 min/km means 5.5 minutes per kilometre. Its speed is 60 / 5.5 = 10.9091 km/h. Pace is the reciprocal view of speed: a lower time per unit distance means a faster rate.
Worked Speed, Distance and Time Examples
Find speed: 100 metres in 9.58 seconds
Using the unrounded result: speed × 3.6 ≈ 37.5783 km/h
This is average speed across the 100-metre interval. It is not the runner's highest or instantaneous speed.
Find distance: 60 mph for 30 minutes
Distance = 60 mi/h × 0.5 h = 30 mi
The distance is 30 international miles, equal to 48.28032 kilometres.
Find time: 100 kilometres at 80 km/h
1.25 h = 1 h 15 min
This is travel time at a constant assumed speed. A real trip may take longer because of stops, traffic, route changes or speed variation.
How to Calculate Average Speed Across a Trip
For several legs, add every distance and add every time. Divide the totals. Do not usually add the leg speeds and divide by the number of legs. Equal durations guarantee that the simple arithmetic mean is correct. Other special cases can coincide, but total distance divided by total time remains the reliable method.
Equal-distance example
A vehicle covers 50 km at 30 km/h, then 50 km at 60 km/h. The first leg takes 100 minutes and the second takes 50 minutes. Total distance is 100 km, while total moving time is 150 minutes or 2.5 hours.
The arithmetic mean of 30 and 60 is 45 km/h, but 45 is wrong here because the vehicle spends twice as long at the slower speed.
Moving average vs elapsed average
Moving average uses the sum of entered leg times. Elapsed average adds stopped time too. If the same 100 km trip includes a 30-minute stop, elapsed time becomes 3 hours and elapsed average speed falls to 33.3333 km/h. The trip mode shows both figures so the definition stays visible.
Every trip leg must contain positive distance and moving time. Enter all rests once in the stopped-time field so the moving average excludes them and the elapsed average includes them. Do not count the same stop in both places.
Supported Speed and Distance Units
The calculator normalizes values before applying a formula. Exact international definitions are used for the inch, foot, yard, mile and nautical mile.
| Speed unit | Metres per second | Useful equivalent |
|---|---|---|
| 1 m/s | 1 | 3.6 km/h |
| 1 km/h | 0.2777777778 | 0.6213711922 mph |
| 1 mph | 0.44704 | 1.609344 km/h |
| 1 ft/s | 0.3048 | 1.09728 km/h |
| 1 knot | 0.5144444444 | 1.852 km/h |
- 1 kilometre = 1,000 metres.
- 1 international foot = 0.3048 metre exactly.
- 1 international mile = 1,609.344 metres exactly.
- 1 international nautical mile = 1,852 metres exactly.
- 1 minute = 60 seconds, 1 hour = 3,600 seconds and 1 day = 86,400 seconds.
These relationships follow the BIPM SI Brochure and the NIST Guide to the SI. Mach is not included because the speed of sound depends on the medium and its conditions.
Speed vs Pace
Speed tells you how much distance is covered per unit time. Pace tells you how much time is required per unit distance. Runners often use minutes per kilometre or minutes per mile. The same movement may be written as 12 km/h, 7.45645 mph, 5:00 min/km or about 8:02.80 min/mi.
Pace per mile = 60 / speed in mph
At zero speed, finite pace is not defined because no distance is being covered. The calculator displays “Not defined” instead of Infinity or 0:00. Clock-style pace input must have seconds below 60. Enter 4:59 or 5:00, not 4:60.
Pace rounding carries correctly. A value close to 59 minutes 60 seconds becomes 60:00 rather than displaying an invalid 59:60. Keep more digits when comparing close performances, then round only the final reported result.
Common Speed Calculation Mistakes
- Mixing incompatible units. Convert minutes to hours before using mph, or let the calculator normalize both inputs.
- Using displacement as distance. Average speed uses total path length. Average velocity uses signed displacement.
- Averaging leg speeds directly. Use total distance divided by total time unless the time at each speed is equal.
- Ignoring stops. Door-to-door average speed includes waiting and rest time. Moving average excludes it.
- Dividing by zero. Speed needs positive elapsed time, and time needs positive speed.
- Entering a negative scalar value. Direction belongs to velocity, not speed or path distance.
- Confusing clock time with duration. 3:30 PM is a time of day. A duration must describe an interval such as 1 hour 20 minutes.
- Rounding early. Keep full conversion precision until the final display.
Accuracy, Rounding and Calculator Limits
The numeric fields accept trimmed decimals and scientific notation. They reject commas, unit text, fractions, incomplete exponents, non-finite values and magnitudes outside the supported range. Hidden fields from another method do not block the active calculation. Any invalid edit clears the previous result, table, steps and copy data.
JavaScript Number arithmetic carries about 15 to 17 significant decimal digits. The page keeps full available precision internally and rounds only for display. Very small valid nonzero results stay visible in scientific notation. A calculated value or unit conversion outside the supported numeric range is reported instead of being shown as zero or infinity.
A precise-looking result is not more accurate than its inputs. Route distance, timing method, GPS sampling, odometer calibration, rounding and stop treatment all affect a real measurement. A planned travel time also assumes the entered speed applies across the full route. It does not predict traffic, safety limits, weather or delays.
This tool handles scalar linear speed. It does not calculate signed velocity, acceleration, angular speed, vector components, relativistic effects, fluid speed, Mach number or uncertainty propagation. Use the Acceleration Calculator when velocity changes with time.
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Speed Calculator FAQs
What is the formula for speed?
Speed equals total distance divided by total elapsed time. Use compatible units before dividing. For example, 100 kilometres in 2 hours gives 50 km/h.
How do I calculate distance from speed and time?
Multiply speed by elapsed time after matching the time unit to the speed unit. At 60 mph for 0.5 hour, distance is 30 miles.
How do I calculate travel time from distance and speed?
Divide distance by speed. At 80 km/h, a 100 km trip takes 1.25 hours, or 1 hour 15 minutes, before any extra stops or delays.
What is average speed?
Average speed is total path distance divided by total elapsed time for the chosen interval. It does not reveal the speed at every moment.
Can I average two speeds by adding them and dividing by two?
Equal durations guarantee that the simple mean is correct. Other special cases can coincide, but the reliable general method is to divide total distance by total time.
What is the difference between speed and velocity?
Speed is a non-negative scalar based on total distance. Velocity includes direction and uses signed displacement. A round trip may have positive average speed but zero average velocity.
What is the difference between speed and pace?
Speed is distance per unit time. Pace is time per unit distance. A faster movement has a higher speed but a lower minutes-per-kilometre or minutes-per-mile pace.
How do I convert m/s, km/h, mph, ft/s and knots?
One m/s equals 3.6 km/h. One mph equals 0.44704 m/s. One ft/s equals 0.3048 m/s. One knot equals 0.5144444444 m/s or 1.852 km/h.
Does stopped time count in average speed?
It counts in elapsed or door-to-door average speed. It is excluded from moving average speed. The trip mode shows both when stopped time is entered.
Can speed be negative?
No. Speed is the magnitude of motion and is non-negative. A negative sign represents direction in velocity or displacement, which is outside this scalar calculator.
Method References
- OpenStax Physics, Speed and Velocity, average-speed formula, speed-versus-velocity distinction and unequal-speed example.
- OpenStax University Physics, Instantaneous Velocity and Speed, scalar speed and whole-interval average speed.
- BIPM SI Brochure, 9th edition, metre, second, m/s, km/h and accepted time and navigation units.
- NIST Guide to the SI, SP 811, international mile, mile per hour and nautical-mile conversion factors.
Disclaimer: This calculator provides educational and preliminary planning results from user-entered values. Verify distance, duration, units, route conditions, measurement uncertainty and applicable safety limits before using a result for travel, sport, laboratory, navigation, machinery or professional work.