Calculate speed, distance, or travel time from any two known values. Convert between mph, km/h, m/s, ft/s, and knots and see the formula used for every result.
Choose a tool below, enter your known values, and press Calculate.
The basic formula behind this entire page is speed equals distance divided by time. If you already know speed and time, you can rearrange the same relationship to find distance, and if you know distance and speed, you can rearrange it again to find time.
Cover the value you want to find. Distance sits alone over Speed multiplied by Time, which is why Speed equals Distance over Time, and Time equals Distance over Speed.
| To Find | Formula |
|---|---|
| Speed | Distance divided by Time |
| Distance | Speed multiplied by Time |
| Time | Distance divided by Speed |
These three relationships are the foundation of the Speed Calculator above. Choose which value you want to solve for, enter the other two, and the calculator fills in the formula for you.
Suppose you travel 150 miles in 2 hours 30 minutes. First convert the time into a single unit: 30 minutes equals 0.5 hour, so the total time is 2.5 hours. Then divide distance by time: 150 divided by 2.5 equals 60 mph.
150 miles divided by 2.5 hours equals 60 mph. The calculator performs this division automatically once you enter hours and minutes separately.
| Distance | Time | Speed |
|---|---|---|
| 150 miles | 2.5 hours | 60 mph |
CalculateThisWay accepts hours, minutes, and seconds as separate fields, so you do not need to convert a time such as 2 hours 30 minutes to decimal hours by hand before entering it.
Use distance equals speed multiplied by time. For example, 60 mph for 2.5 hours gives 60 times 2.5, which equals 150 miles. The units have to be compatible: if speed is measured in miles per hour, time should be represented in hours before multiplying. The calculator converts hours, minutes, and seconds internally so you never have to do that conversion yourself.
Use time equals distance divided by speed. For example, 150 miles at 60 mph gives 150 divided by 60, which equals 2.5 hours, or 2 hours 30 minutes.
100 divided by 60 equals about 1.6667 hours. The decimal part, 0.6667 hour, multiplied by 60 is approximately 40 minutes. So the answer is approximately 1 hour 40 minutes. This assumes a constant 60 mph average with no stopped time. Real travel can take longer because of traffic, signals, stops, speed changes, and road conditions.
Instantaneous speed is the speed at one single moment, the number you would see on a speedometer right now. Average speed is total distance divided by total elapsed time across an entire trip. A vehicle may show 65 mph on the speedometer at one moment while the trip's overall average speed is only 48 mph, because of slower sections, traffic, or stops along the way.
Suppose you travel 60 miles at 60 mph, which takes 1 hour, and then 60 miles at 30 mph, which takes 2 hours. Total distance is 120 miles. Total time is 3 hours. Average speed is 120 divided by 3, which equals 40 mph.
The simple arithmetic average of 60 mph and 30 mph is 45 mph, but that is wrong for this trip because the vehicle spent twice as long at the slower speed. The correct average speed is total distance over total time, which is 40 mph.
| Segment | Distance | Time |
|---|---|---|
| Segment 1 | 60 miles at 60 mph | 1 hour |
| Segment 2 | 60 miles at 30 mph | 2 hours |
| Total | 120 miles | 3 hours |
| Correct average speed | 120 miles ÷ 3 hours = 40 mph | |
| Incorrect simple average | (60 + 30) ÷ 2 = 45 mph, not used here | |
The simple arithmetic average, (60 + 30) divided by 2, equals 45 mph, which is wrong for this trip because the vehicle spent different amounts of time at each speed. The Average Speed tool above never performs this kind of averaging. It only adds distances, adds times, and divides.
Add all the distances together. Add all the elapsed times together. Then divide total distance by total time. CalculateThisWay's Average Speed tool performs exactly that calculation and never averages the individual segment speeds.
Moving average speed excludes stopped time. For example, suppose total distance is 120 miles, moving time is 2 hours 30 minutes, and stopped time is 30 minutes. Moving average speed is 120 divided by 2.5, which equals 48 mph. Elapsed average speed is 120 divided by 3, which equals 40 mph. Both numbers can be useful. They answer different questions: one describes how fast you traveled while moving, and the other describes your overall pace door to door.
Speed answers "how much distance per unit of time," such as 60 miles per hour or 10 kilometers per hour. Pace answers "how much time per unit of distance," such as 10 minutes per mile. CalculateThisWay has a dedicated Pace Calculator for running, walking, and fitness pacing. Use this Speed Calculator for general distance, time, and speed problems involving cars, bicycles, boats, and everyday math.
Speed tells you how fast something is moving. Velocity includes both speed and direction. For example, 60 mph is a speed. 60 mph north includes direction and describes a velocity. This page performs scalar speed calculations only. It does not solve full vector-motion problems.
Speed is a single number describing how fast. Velocity adds a direction on top of that same number. This calculator works with speed, not vector velocity.
| Term | What It Includes |
|---|---|
| Speed | How fast, a single non-negative number such as 60 mph |
| Velocity | Speed plus a direction, such as 60 mph north |
NIST gives 1 mph as exactly 1.609344 km/h. So 60 mph equals 60 times 1.609344, which equals 96.56064 km/h, typically displayed as 96.56 km/h.
The same speed expressed in three common units, using exact NIST conversion factors.
| Unit | Value |
|---|---|
| Miles per hour | 60 mph |
| Kilometers per hour | 96.56064 km/h |
| Meters per second | 26.8224 m/s |
Divide by 1.609344. For example, 100 km/h divided by 1.609344 is approximately 62.1371 mph.
NIST gives 1 mph as exactly 0.44704 m/s. So 60 mph equals 26.8224 m/s.
Reverse the conversion by dividing by 0.44704. For example, 10 m/s divided by 0.44704 is approximately 22.369 mph.
A knot is one nautical mile per hour. A nautical mile is defined as exactly 1,852 meters. NIST gives a knot as approximately 0.514444 m/s. Knots are commonly used for marine navigation, aviation, and weather reporting. They are not the same as miles per hour.
Yes. If distance traveled is zero over a positive period of time, average speed is zero. However, if time is zero and distance is positive, the standard formula would require dividing by zero. This calculator rejects that input rather than displaying an error value such as Infinity.
Common units include miles per hour, kilometers per hour, meters per second, feet per second, and knots. A reliable calculator converts every value through a consistent base unit, meters per second, before returning the requested unit. This page does exactly that internally.
It can calculate theoretical travel duration from distance and an entered average speed. It cannot predict traffic, weather, construction, or stops. The result is best described as travel time at the entered average speed, not a guaranteed arrival time.
A speed input such as 60 mph usually represents an average speed for the calculation. A road trip rarely maintains exactly 60 mph for every second. Real travel includes acceleration, slowing, traffic, signals, and rest stops. The calculator solves the mathematical relationship between speed, distance, and time, not real-world traffic conditions.
Speed Calculator solves for speed, distance, or time from the other two known values and includes speed unit conversions for convenience. The Unit Converter simply converts one known speed unit into another and covers many more categories of measurement, including length, weight, temperature, volume, and area. This page includes speed conversions for convenience but links to Unit Converter for broader measurement conversion.
Use Speed Calculator for cars, bicycles, boats, general motion, school math, and distance or time problems. Use the Pace Calculator for minutes per mile, minutes per kilometer, and running or walking pacing for fitness goals.
The core formulas are speed equals distance divided by time, distance equals speed multiplied by time, and time equals distance divided by speed. For multiple segments, average speed equals total distance divided by total time. CalculateThisWay accepts practical mixed time formats, converts speed units accurately using exact NIST factors, and always shows the math behind every result.
The examples below use the exact same calculation engine as the calculator above, computed live in the page, so they will always match what the calculator returns for these inputs.
150 miles traveled in 2 hours 30 minutes.
Traveling at 60 mph for 2 hours 30 minutes.
150 miles and 100 miles, both at 60 mph.
60 mph converted to other units, and 100 km/h converted to mph.
60 miles at 60 mph, then 60 miles at 30 mph.
You drive 220 miles in 3 hours 40 minutes. What is your average speed in miles per hour?
I want to solve speed, distance, or time, convert speed units, or find average speed across multiple segments.
I want running, walking, or fitness pacing in minutes per mile or minutes per kilometer.
I want to convert length, weight, temperature, volume, area, or speed between many different units.
I want to add, subtract, or find the difference between dates and times, unrelated to speed or distance.
The basic speed formula is speed equals distance divided by time. If you know distance and speed instead, distance equals speed multiplied by time, and time equals distance divided by speed.
Divide the distance traveled by the time it took. For example, 150 miles traveled in 2 hours 30 minutes, which is 2.5 hours, gives 150 divided by 2.5, or 60 mph.
Multiply speed by time, making sure the time unit matches the speed unit. For example, 60 mph for 2.5 hours gives 60 times 2.5, or 150 miles.
Divide distance by speed. For example, 150 miles at 60 mph gives 150 divided by 60, or 2.5 hours, which is 2 hours 30 minutes.
Add up the total distance from every segment of the trip, add up the total elapsed time, then divide total distance by total time. This calculator's Average Speed tool performs exactly that calculation.
A simple average of two speeds only works when equal amounts of time are spent at each speed. If you drive 60 miles at 60 mph, that takes 1 hour, and 60 miles at 30 mph takes 2 hours. Total distance is 120 miles over 3 hours, for an average of 40 mph, not the simple average of 45 mph, because more time was spent at the slower speed.
It is the formula for true average speed across an entire trip or activity. It is more accurate than averaging individual speed readings because it automatically accounts for how long you traveled at each speed.
100 divided by 60 equals about 1.6667 hours, which is approximately 1 hour 40 minutes, assuming a constant 60 mph average with no stops.
150 divided by 60 equals 2.5 hours, which is exactly 2 hours 30 minutes, assuming a constant 60 mph average with no stops.
60 multiplied by 2 equals 120 miles, assuming a constant 60 mph average for the full 2 hours.
This calculator accepts hours, minutes, and seconds as separate fields, so you can enter a time such as 2 hours 30 minutes directly without converting it to decimal hours yourself.
Divide the number of minutes by 60. For example, 30 minutes divided by 60 equals 0.5 hour, so 2 hours 30 minutes equals 2.5 hours.
Multiply by 1.609344, the exact NIST conversion factor. For example, 60 mph times 1.609344 equals 96.56064 km/h.
Divide by 1.609344. For example, 100 km/h divided by 1.609344 is approximately 62.1371 mph.
Multiply by 0.44704, the exact NIST conversion factor. For example, 60 mph times 0.44704 equals 26.8224 m/s.
Divide by 0.44704. For example, 10 m/s divided by 0.44704 is approximately 22.369 mph.
Convert both units to meters per second using the nautical mile definition of 1,852 meters, then compare. The calculator and converter above do this automatically.
A knot is one nautical mile per hour. A nautical mile is defined as exactly 1,852 meters, which makes one knot approximately 0.514444 meters per second. Knots are commonly used in marine navigation, aviation, and weather reporting.
Speed is a scalar that describes how fast something is moving. Velocity includes both speed and direction. This calculator computes scalar speed and does not solve vector velocity problems.
Speed answers how much distance is covered per unit of time, such as 60 miles per hour. Pace answers how much time it takes to cover one unit of distance, such as 10 minutes per mile. CalculateThisWay has a separate Pace Calculator for running, walking, and fitness pacing.
Moving average speed is total distance divided by moving time only, excluding any time spent stopped. It describes how fast you traveled while actually in motion.
Elapsed average speed is total distance divided by total elapsed time, including any stopped or break time. It describes your overall pace for the entire trip, door to door.
Yes. Including stopped time in the denominator lowers the elapsed average speed compared with the moving average speed. Neither number is universally more correct, since they answer different questions.
Yes. If distance traveled is zero over a positive period of time, average speed is zero. This calculator allows a zero result.
Time can be zero when calculating distance, since zero time simply produces zero distance. However, time cannot be zero when calculating speed, because dividing distance by zero time is undefined, so the calculator rejects that input.
No. This calculator treats speed as a non-negative scalar and does not accept negative distance, time, or speed values.
It calculates theoretical travel duration at an entered average speed, which can be labeled travel time at entered average speed. It is not a guaranteed arrival time, since it cannot predict traffic, weather, construction, or stops.
The calculator solves the mathematical relationship between speed, distance, and time. It does not model traffic, signals, weather, or road conditions, so real travel time can differ from the calculated result.
Speed Calculator solves general speed, distance, and time problems for cars, bicycles, boats, and everyday math. Pace Calculator is built for running, walking, and fitness pacing in minutes per mile or minutes per kilometer.
Speed Calculator solves for speed, distance, or time from the other two values and includes speed unit conversions for convenience. Unit Converter is a broader tool for converting many kinds of measurements, including length, weight, temperature, volume, area, and speed.