Find speed, distance or time from the other two, work out average speed over several legs, and see the answer in mph, km/h, m/s, ft/s and knots.
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Find Speed, Distance or Time
150 miles in 3 h, the speed is
50 mph
That is a pace of 1:12 per mile, or 0:45 per km.
Kilometers per hour80.4672 km/h
Meters per second22.352 m/s
Feet per second73.333333 ft/s
Knots43.448812 kn
Pace per mile1:12 min
Pace per km0:45 min
Time in minutes180 min
Distance in km241.4016 km
The working: 150 miles ÷ 3 h = 50 mph
Time can be hours, minutes and seconds. Distance can be miles, kilometers, meters, feet, yards or nautical miles. Press Calculate after you change the numbers.
About Speed Calculator
Speed is how far you go in each unit of time. Give any two of distance, speed and time and the calculator finds the third, then shows the answer in other speed units and as a running pace. The second tab finds the average speed over several legs.
The Formula
Speed =distancetime
Distance = speed × time
Time =distancespeed
Speed in mph, km/h, m/s, ft/s or knots
Distance in miles, km, m, ft, yd or nautical miles
Time in hours, minutes and seconds
Good to Know
✓Keep the units together: miles and hours give mph
✓Average speed is total distance ÷ total time
✓60 mph out and 40 mph back averages 48 mph, not 50
✓Speed is how fast; velocity adds a direction
Speed, Distance, Time Triangle
Cover the letter you want. What is left shows the formula: D over S × T gives speed = D ÷ T.
Speed = distance ÷ time
Distance = speed × time
Time = distance ÷ speed
D = distance, S = speed, T = time. Keep the units the same: miles with hours give mph, km with hours give km/h.
Speed Formulas
The formulas as a table, with an example for each.
To find
With these
Formula
Example
Speed
Distance, time
S = D ÷ T
150 mi ÷ 3 h = 50 mph
Distance
Speed, time
D = S × T
60 mph × 2.5 h = 150 mi
Time
Distance, speed
T = D ÷ S
100 mi ÷ 60 mph = 1 h 40 min
Average speed
Total D, total T
total D ÷ total T
125 mi ÷ 2.75 h = 45.454545 mph
mph = miles ÷ hours, km/h = kilometers ÷ hours, m/s = meters ÷ seconds.
Average Speed over Several Legs
The Average Speed tab takes up to 10 legs. Average speed is the total distance divided by the total time, not the average of the speeds.
Leg
Distance
Time
Speed
Leg 1
60 miles
1 h 15 min
48 mph
Leg 2
40 miles
1 h
40 mph
Leg 3
25 miles
30 min
50 mph
Total: 125 miles in 2 h 45 min = 45.454545 mph
The average of 48, 40 and 50 mph would be 46 mph, which is wrong. A round trip at 60 mph out and 40 mph back averages 48 mph, not 50: the slower part takes more time.
How Long Does a Trip Take?
The time for a distance at a speed in mph.
Distance
30 mph
45 mph
55 mph
60 mph
65 mph
70 mph
75 mph
10 miles
20 min
13 min
11 min
10 min
9 min
9 min
8 min
25 miles
50 min
33 min
27 min
25 min
23 min
21 min
20 min
50 miles
1 h 40 min
1 h 7 min
55 min
50 min
46 min
43 min
40 min
100 miles
3 h 20 min
2 h 13 min
1 h 49 min
1 h 40 min
1 h 32 min
1 h 26 min
1 h 20 min
150 miles
5 h
3 h 20 min
2 h 44 min
2 h 30 min
2 h 18 min
2 h 9 min
2 h
200 miles
6 h 40 min
4 h 27 min
3 h 38 min
3 h 20 min
3 h 5 min
2 h 51 min
2 h 40 min
300 miles
10 h
6 h 40 min
5 h 27 min
5 h
4 h 37 min
4 h 17 min
4 h
500 miles
16 h 40 min
11 h 7 min
9 h 5 min
8 h 20 min
7 h 42 min
7 h 9 min
6 h 40 min
Time = distance ÷ speed, rounded to the minute.
Dash Time at a Given Speed
How many seconds a 40-yard dash or a 100 m sprint takes at a speed, such as 23 mph.
Speed
In km/h
40 yards
100 meters
15 mph
24.14016 km/h
5.455 s
14.913 s
18 mph
28.968192 km/h
4.545 s
12.427 s
20 mph
32.18688 km/h
4.091 s
11.185 s
22 mph
35.405568 km/h
3.719 s
10.168 s
23 mph
37.014912 km/h
3.557 s
9.726 s
25 mph
40.2336 km/h
3.273 s
8.948 s
40 yards is 36.576 m. These are average speeds over the whole run, not top speed.
Speed from a 40-Yard Dash Time
Time
Speed in mph
Speed in km/h
4.2 s
19.481 mph
31.351 km/h
4.4 s
18.595 mph
29.926 km/h
4.6 s
17.787 mph
28.625 km/h
4.8 s
17.045 mph
27.432 km/h
5 s
16.364 mph
26.335 km/h
5.5 s
14.876 mph
23.941 km/h
Speed = 36.576 m ÷ time.
How Far at a Steady Speed?
Speed
In 1 hour
In 24 hours
1 hour in km
10 mph
10 miles
240 miles
16.09344 km
30 mph
30 miles
720 miles
48.28032 km
55 mph
55 miles
1,320 miles
88.51392 km
60 mph
60 miles
1,440 miles
96.56064 km
70 mph
70 miles
1,680 miles
112.65408 km
Other Speed Tools
Need the speed in other units? Use the Speed Converter for mph, km/h, m/s, ft/s, knots and Mach. For minutes per mile or per km and race times, use the Pace Calculator. To add or subtract times, use the Time Calculator.
Good to know
Pick what to find, then fill in the other two. Time can be hours, minutes and seconds.
Change the units any time. The answer is shown in the unit you choose, and in the other speed units under it.
Press Calculate after you change the numbers. Switching between Speed, Distance and Time shows that answer straight away.
It cannot measure how fast you are going now, and it cannot look up the distance between two places.
What is included
Speed, distance or time from the other two
Average speed over up to 10 legs
The answer in mph, km/h, m/s, ft/s and knots
Pace per mile and per km
Trip, dash and distance tables
Copy link and print
Important to know
Your numbers stay in your own browser and are never sent anywhere. Dash times are averages over the whole run; a sprinter's top speed is higher.
Use this free speed calculator to find speed, distance or time. Choose what you want to find, fill in the other two, and press Calculate to see the answer with the working shown. Time can be hours, minutes and seconds, and distance and speed can be miles, kilometers, meters, feet, yards, nautical miles, mph, km/h, m/s, ft/s or knots. The answer is also shown in the other speed units and as a pace per mile and per km. The Average Speed tab finds the average over up to 10 legs of a trip, and shows why it is not the average of the speeds. Tables list how long a trip takes at common speeds, what a speed covers in an hour and a day, and dash times at a given speed. It is free and instant, and your numbers stay in your browser.
How to calculate speed
Divide the distance by the time. Speed tells you how far something goes in each unit of time.
speed = distance ÷ time
For 150 miles in 3 hours: 150 ÷ 3 = 50 mph. In other units that is 80.4672 km/h, 22.352 m/s and 73.333333 ft/s. Keep the units together: miles and hours give mph, kilometers and hours give km/h, meters and seconds give m/s.
How to find distance
Multiply the speed by the time: distance = speed × time. At 60 mph for 2.5 hours you travel 60 × 2.5 = 150 miles. At 55 mph for 1 hour 30 minutes it is 82.5 miles.
How to find time
Divide the distance by the speed: time = distance ÷ speed. A 100-mile trip at 60 mph takes 100 ÷ 60 = 1.666667 hours, which is 1 hour 40 minutes. The "How Long Does a Trip Take?" table above lists common distances and speeds.
Average speed
Average speed is the total distance divided by the total time. It is not the average of the speeds. If you drive 60 miles in 1 hour 15 minutes, 40 miles in 1 hour and 25 miles in 30 minutes, you have gone 125 miles in 2 hours 45 minutes, so the average speed is 125 ÷ 2.75 = 45.454545 mph, while the plain average of 48, 40 and 50 mph is 46 mph. The Average Speed tab does this for up to 10 legs.
A round trip is the classic trap. Driving 60 mph out and 40 mph back over the same road gives an average of 2 ÷ (1/60 + 1/40) = 48 mph, not 50, because you spend more time at the slower speed.
Speed units
The calculator works in miles, kilometers, meters, feet, yards and nautical miles for distance, and mph, km/h, m/s, ft/s and knots for speed. One mph is exactly 1.609344 km/h, and 60 mph is exactly 88 ft/s. To change a speed from one unit to another, use the Speed Converter.
Dash times at a given speed
A 40-yard dash is 36.576 meters. At an average of 23 mph (10.28 m/s) it takes 3.557 seconds, and 100 meters at 22 mph takes 10.168 seconds. These are average speeds over the whole run. A sprinter starts from rest, so the top speed is higher than the average.
Speed and velocity
Speed is how fast you move. Velocity is speed in a given direction. This calculator finds the size of the speed. For running pace in minutes per mile or per kilometer, use the Pace Calculator, and to add or subtract lengths of time use the Time Calculator.
What this calculator cannot do
It works out a speed, a distance or a time from numbers you give it. It cannot measure how fast you are going now (your phone's speedometer or GPS does that), and it cannot look up the distance between two places. You can type a distance you already know, such as 10 miles.
Divide the distance by the time. For 150 miles in 3 hours the speed is 150 ÷ 3 = 50 mph. Choose Speed in the calculator, fill in the distance and the time, and it shows the working and the answer in other units.
What is the formula for speed, distance and time?
Speed = distance ÷ time. From it, distance = speed × time and time = distance ÷ speed. Keep the units together: miles and hours give mph, kilometers and hours give km/h, meters and seconds give m/s.
How do I find the distance from speed and time?
Multiply the speed by the time. At 60 mph for 2.5 hours you travel 60 × 2.5 = 150 miles. Choose Distance in the calculator, fill in the speed and the time, and pick the unit you want the answer in.
How do I find the time from distance and speed?
Divide the distance by the speed. A 100-mile trip at 60 mph takes 100 ÷ 60 = 1.666667 hours, which is 1 hour 40 minutes. Choose Time in the calculator and fill in the distance and the speed.
How do I find average speed?
Divide the total distance by the total time. If you drive 60 miles in 1 h 15 min, 40 miles in 1 h and 25 miles in 30 min, that is 125 miles in 2 h 45 min, so 125 ÷ 2.75 = 45.454545 mph. The Average Speed tab does this for up to 10 legs.
Why is average speed not the average of the speeds?
Because you spend more time at the slower speed. Driving 60 mph out and 40 mph back over the same road gives an average of 48 mph, not 50. The average of the speeds only works when each part takes the same time.
How do I calculate miles per hour?
Divide the miles by the hours. 150 miles in 3 hours is 50 mph, and 10 miles in 20 minutes is 10 ÷ (20 ÷ 60) = 30 mph. Type the time in minutes or seconds and the calculator changes it to hours for you.
How long does it take to travel 100 miles at 60 mph?
1 hour 40 minutes (100 ÷ 60 = 1.666667 hours). At 55 mph it takes 1 hour 49 minutes, at 70 mph 1 hour 26 minutes and at 30 mph 3 hours 20 minutes. The trip table above lists more distances.
How many seconds is a 40-yard dash at 23 mph?
3.557 seconds. A 40-yard dash is 36.576 meters and 23 mph is 10.28192 m/s, so the time is 36.576 ÷ 10.28192. At 20 mph it is 4.091 seconds. These are average speeds over the whole run, not top speed.
How do I convert speed to km/h or m/s?
Multiply mph by 1.609344 for km/h, or by 0.44704 for m/s. The answer on this page is also shown in the other speed units. For a full list including knots and Mach, use the Speed Converter.
What is constant speed?
Constant speed means the speed does not change, so the distance grows by the same amount in each equal time. At a constant 60 mph you cover 60 miles every hour. With a constant speed, the average speed equals the speed.
What is the difference between speed and velocity?
Speed is how fast something moves. Velocity is speed in a given direction. The units are the same, such as m/s or mph, and this calculator finds the size of the speed.
How do I find the speed from minutes per mile?
Divide 60 by the minutes per mile. A 10-minute mile is 6 mph and an 8-minute mile is 7.5 mph. The Pace Calculator changes between pace, mph and km/h and shows your splits.
How far did I run?
Multiply your speed by the time: running at 6 mph for 45 minutes is 6 × 0.75 = 4.5 miles. Choose Distance, fill in the speed and the time, and the answer appears. If you do not know your speed, the Pace Calculator works from your pace.
Can this calculator tell me how fast I am going now?
No. It works out a speed from a distance and a time that you enter. To see how fast you are going now, use the speedometer in your car or the speed shown by your phone's map or fitness app, which uses GPS.
Are my numbers saved or shared?
No. The calculation happens in your browser, and the numbers you type are not stored or sent to any server. A link you copy keeps the numbers after the # sign, which browsers never send to a server.
