During these challenging times, we guarantee we will work tirelessly to support you. We will continue to give you accurate and timely information throughout the crisis, and we will deliver on our mission — to help everyone in the world learn how to do anything — no matter what. Thank you to our community and to all of our readers who are working to aid others in this time of crisis, and to all of those who are making personal sacrifices for the good of their communities.

We will get through this together. Updated: April 11, References. Speed is the measure of how fast something is going at a certain time. If you've ever looked at a car's speed gauge while it's moving, you've seen speed being measured — the farther the needle goes, the higher the car's speed is.

There are a few different ways to calculate speed depending on which types of information you have. Note: This section uses techniques that may be unfamiliar to those who have not studied calculus.

See our calculus articles for help. To calculate the speed on an object, start by determining how far the object has traveled. Next, figure out the amount of time that the object took to cover that distance. Finally, divide the distance the object traveled by the time it took to get there. Don't forget to label the speed with the correct units of measurement.

For example, if a car traveled miles and it took 2 hours to make the trip, you would divide miles by 2 hours to get 50 miles per hour. For tips on how to convert units, such as miles per hour to kilometers per hour, read on! Did this summary help you? Yes No. Log in Facebook Loading Google Loading Civic Loading No account yet? Create an account. We use cookies to make wikiHow great. By using our site, you agree to our cookie policy.

As the COVID situation develops, our hearts ache as we think about all the people around the world that are affected by the pandemic Read morebut we are also encouraged by the stories of our readers finding help through our site. Article Edit. Learn why people trust wikiHow.Contact Us Blog. This calculator is used to calculate the speed of a vehicle traveling over one or more surface types and takes into account an impact with another vehicle or object.

This calculator can be used if there aren't multiple roadway surface types or an impact. In this situation just leave the extra input fields empty. Use negative sign - for downhill grade. Example: 2.

### Speed, Distance & Time Calculator

The friction table below can be used to approximate the roadway friction based upon different roadway surface types and whether or not the surface is wet or dry. Atlanta Engineering Services, Inc. This tool shall not be used for any insurance or litigation purposes. The accident scene investigation.

Learn how a vehicle black box and it's downloads can prove up evidence. View a sample engineering report here. Calculating the stopping distance.

Multiple surfaces calculator to determine the stopping distance when there is more to consider. How a vehicle inspection analysis can help you after an accident. Reconstructing accidents involving Non-Commercial trucks. Read how vehicle defects can be the cause of a traffic accident here. It just may be those roadway ruts that caused you to hydroplane, find out more here.

Was it poor design or layout that caused the accident? See real 3D accident simulations with this link. More 3D accident reconstruction videos can be found here. See actual photos of traffic accidents here. Atlanta Engineering Services. Peachtree Corners, GA Vehicle Speed Calculator over Multiple Surfaces with an Impact This calculator is used to calculate the speed of a vehicle traveling over one or more surface types and takes into account an impact with another vehicle or object.

Vehicle speed calculator Accidents involving motorcycles How a vehicle inspection analysis can help you after an accident Reconstructing accidents involving Non-Commercial trucks Read how vehicle defects can be the cause of a traffic accident here. It just may be those roadway ruts that caused you to hydroplane, find out more here Was it poor design or layout that caused the accident?

See real 3D accident simulations with this link More 3D accident reconstruction videos can be found here See actual photos of traffic accidents here. Vehicle speed calculator. Accidents involving motorcycles How a vehicle inspection analysis can help you after an accident Reconstructing accidents involving Non-Commercial trucks Read how vehicle defects can be the cause of a traffic accident here.By using our site, you acknowledge that you have read and understand our Cookie PolicyPrivacy Policyand our Terms of Service.

It only takes a minute to sign up. While I was driving my car suddenly the left control arm suddenly broke off the car has had a curb accident on that side before and the cv-joint de-attached from the transmission and the car was not moving anymore while in gear. But something I noticed is the vehicle speedometer was relative to the RPM; as the car was in gear and increasing the RPM the speedometer was functioning as if the vehicle was in motion. So does the ECU just use the rpm, gear ratio of the current gear and final drive ratio to calculate vehicle speed?

If the ECU would calculate speed from RPM, how would it calculate speed when the car is in neutral or during shifting? The speed usually is derived from the RPM of the output shaft of the transmission to the differential.

This way, one gets an average of the speed of the left and right wheels. The key to your observation is the differential. It distributes the power to the left and right wheel while allowing both wheels to turn independently. When one wheel is on the ground and the other is lifted, only the lifted wheel will turn when the motor is running and the transmission in gear, while the other stands still.

The speedometer will indicate a speed because the shaft to the differential is spinning, while the wheel turns with twice this speed. Remember: Displayed speed is average of left and right wheel. Somewhere there is a signal that measures rotating speed on the driveline, downstream of the torque converter.

## How to calculate vehicle speed from engine RPM and vice versa

It is typically somewhere inside the transmission housing. Because of how a torque converter operates, engine RPM would not be a totally great indicator for vehicle speed. Typically auto manufacturers use a hall effect sensor to determine spinning shaft speed.

Those sensors are pretty cheap. Having one sensor for engine RPM, and another for vehicle speed would give great feedback to the engine control computer on the functioning of both the engine AND the transmission, including torque converter.

An ABS vehicle has a notched ring at each wheel, with hall effect sensor and is used to determine the speed of that individual wheel. By looking at the averages from all four wheels, a computer can determine vehicle speed.

I've seen vehicles with hall effect speed sensors on Camshaft, Crankshaft, transmission output shaft and ABS wheel sensors The speedometer is generally connected somewhere after the gearbox eg the driveshaft.

So in normal circumstances this is directly proportional to the angular velocity of the wheels, depending on the differential ratio and assuming no wheel slip. This needs to be somewhere between the clutch and the differential otherwise it would jump around whenever the clutch was disengaged. Placing it after the gearbox also removes the need to sense and compensate for individual gear ratios which would be more difficult in a mechanical system.

The relationship between torque and rpm is irreverent here as the speedometer is calibrated from the rotational speed of the wheels and their diameter.Use this speed calculator to easily calculate the average speed, distance travelled and the trip duration of a vehicle: car, bus, train, bike, motorcycle, plane etc.

Works with miles, feet, kilometers, meters, etc. You will need to convert the metrics to the same time and distance units, e. For example, if you have speed in mph miles per hourtime should also be in hours. The unit of the result will depend on the units you input, but our speed calculator will conveniently display additional units where appropriate. As noted above, make sure you convert the units appropriately first, or use our speed calculator which does that automatically. The resulting unit will depend on the units for both time and distance, so if your input was in miles and hours, the speed will be in mph.

Example: If you took a plane from New York to Los Angeles and the flight was 5 hours of air time, what was the speed of the plane, given that the flight path was miles? As usual, make sure that the time unit of the speed measure is the same as the time unit for the duration of the trip. Our distance calculator will sometimes output the distance in more than one unit, for your convenience.

Example: If a truck travelled at an average speed of 80 km per hour for 4 hours, how many miles did it cover in that time?

The time, or more precisely, the duration of the trip, can be calculated knowing the distance and the average speed using the formula:.

Make sure you convert the units so both their distance and time components match, or use our trip duration calculator above which will handle conversions automatically. The time unit of the result will match the time unit of the speed measure, so if it is measured in something per hour, the result will be in hours. If it is measured in some unit per second, the result will be in seconds. Example: If a train can travel miles with an average speed of 50 miles per hour, how long it would take it to complete a mile route?

Say you travelled a certain distance with a car or another vehicle and you want to calculate what its average speed was. The easiest way to do that would be by using the speed, distance, and time calculator above, but if you prefer, you can also do the math yourself.

Either way, you need to know the distance to a satisfactory approximation, for which you can use a map e. Google Maps to measure the distance from point to point. Make sure you measure closely to the path you took, and not via a straight line, unless you travelled by air in which case that would be a good approximation.

Of course, having a GPS reading of the distance would be more precise. Then you need to know the travel time. Make sure you subtract any rests or stops you made from the total trip duration.

If you'd like to cite this online calculator resource and information as provided on the page, you can use the following citation: Georgiev G. Calculators Converters Randomizers Articles Search. Time Duration. Share calculator:. Embed this tool! Related calculators Speed Calculator Acceleration Calculator.

How to calculate the average speed of a car?All Rights Reserved. The material on this site can not be reproduced, distributed, transmitted, cached or otherwise used, except with prior written permission of Multiply. Hottest Questions. Previously Viewed.

Unanswered Questions. What is the formula to determine the speed of a vehicle? Wiki User The tachometer measures the number of revolutions the engine makes in a minute.

This indirectly equates to the speed of the vehicle. Depending on the gear that the vehicle is in, you could determine speed with a tachometer. To determine your speed, you would need to know the gearing of the rear end as well as the circumference of the wheels. Asked in Physics How can the average speed of an object be used to determine an unmeasured distance?

The time should also be known for this formula to work. Insurance companies will determine that your car is totaled if the cost of the damage approaches or exceeds the car. If the cost to repair is more than the vehicle is worth to replace then it is considered totaled. Asked in Rules of the Road The speed limit maximum when driving a vehicle on a taxiway or an inactive runway is?

Asked in Driving Times How many hours will it take you to drive miles on a highway? The answer requires more information. The formula for this is called the "time, speed, distance" formula. You need 2 elements to calculate the answer.This speed calculator is a tool that helps you determine the average speed of a moving object based on the distance traveled over a certain time traveled. Whether you are test driving your brand new caror just going for a quick jog or cycle, if you want to know how to find average speed, this calculator will come in handy.

In the article below, you can find a lot of valuable information, like what the average speed formula is. We will also give you a few curious speed facts e. Check this speed distance calculator and finally find an answer to the question how fast am I going? We have all heard of speedbut how confident are you in your understanding of this concept?

Speed is, by definition, purely related and connected to physics. However, when you take the time to think about it, you don't see the vectors and formulas from your textbook, but instead a cyclist, flying jet or speedometer needle.

We mostly associate speed with moving objects than with scientific equations. What is more, we have a sense that tells us how quickly we are traveling at, that is we can sense whether we are moving fast or not. So, we can say that the human perception of speed is relative. Automobiles and trains measure speed in kilometers per hour kph or in miles per hour mphand on airplanes and ships we usually use knots kn.

The speed definition hides behind these units, and we can get familiar with it by examining them. Everything about speed is related to distance and time. The units of speed are specified by traveled distance units divided by units of time, and that is the general idea of speed.

In a more simple way - speed is the distance traveled per unit of time. Speed is not a precise term - there are a few more accurate meanings, and they should not be confused with each other. Let's consider the differences between instantaneous speedaverage speed and rotational speed.

For the purpose of two first, we will try to visualize it with an example of driving a car. You are driving along the long, open highway. You glance down at the speedometer of your car; it reads kilometers per hour. From this, you know how far you will drive if you keep the speed constant. We know that, in practice, keeping the speed exactly constant is almost impossible although, on a highway with cruise control, it is nearly possibleand our speed fluctuates all the time, more or less.

The actual distance you travel in an hour is the average of all these speeds.During these challenging times, we guarantee we will work tirelessly to support you. We will continue to give you accurate and timely information throughout the crisis, and we will deliver on our mission — to help everyone in the world learn how to do anything — no matter what.

Thank you to our community and to all of our readers who are working to aid others in this time of crisis, and to all of those who are making personal sacrifices for the good of their communities.

**How to Calculate HORSE-POWER (hp) of Car Engine**

We will get through this together. Updated: March 9, References. But sometimes you are given two different speeds used for some periods of time, or over some distances.

In these instances, other formulas exist for calculating the average speed. These types of problems might be useful to you in real life, and often appear on standardized tests, so it is helpful to learn these formulas and methods.

If you need to calculate average speed and you know the total distance covered and the total time it took to cover that distance, divide the distance into the total time.

The result will be the average speed per unit of time, usually an hour. If you want to learn how to calculate average speed if there are multiples distances or amounts of time, keep reading the article! Did this summary help you? Yes No. Log in Facebook Loading Google Loading Civic Loading No account yet? Create an account. We use cookies to make wikiHow great. By using our site, you agree to our cookie policy.

## How to Determine Speed in an Accident Investigation?

As the COVID situation develops, our hearts ache as we think about all the people around the world that are affected by the pandemic Read morebut we are also encouraged by the stories of our readers finding help through our site. Article Edit. Learn why people trust wikiHow. This article was co-authored by our trained team of editors and researchers who validated it for accuracy and comprehensiveness. Together, they cited information from 8 references. Learn more Given Two Speeds for Half the Time.

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