This online velocity converter uses definitions for the units of speed as they are established by international treaty in 1959 and as defined by the International System of Units (SI) ^[1] whose definitions are followed universally around the world. It is also in accord with the ISO standards for quantities and units ^[2]. The symbol convention is the one defined by SI. In some locations the standards may not be followed on a regular basis, e.g. the same symbol: "m", may be used for both miles and meters, causing potential confusion like between "mph" being used both for miles per hour and for meters per hour. Given the relative rarity of the latter unit, it is usually safe to assume "mph" stands for miles per hour.

The conversion output is accurate to ten decimal places: more than enough for most applications where a speed converter is needed.

Some of you might be wondering about the difference between velocity and speed. Velocity is basically a directed movement with a certain speed, while speed, being a description of the magnitude of the velocity, has no direction (it is a scalar quantity).

Speed conversion. Imperial vs. Metric units.

Since 1959 both metric and imperial units of speed are defined using the standard meter (metre in British English) as a base unit. Consequently, all metric units for measuring velocity are expressed relative to it, e.g. a kilometer is 1,000 meters. To convert between metric units one needs to take into account the length dimension and the time dimension. E.g. in converting meters per second to km per hour, you need to multiply by 3600 to account for the 3600 seconds in an hour, and also divide by 1,000 to account for the length dimension, resulting in a multiplication by 3.6 (see more examples below). The same logic of conversion applies to conversions from one imperial unit to another, with both dimensions taken into account.

Imperial units can trace their lineage further back in history but are currently in official use only in the United States, United Kingdom, and a couple of other countries, while the metric system is official in the rest of the world. Using a speed converter can be considered one way to bring these countries closer together, as it doesn't seem either side is willing to forgo its speed unit system.

When converting from metric to imperial or from imperial to metric units of speed, the logic is the same, only the multiplication or division factor is different. Since all imperial units are defined in terms of the meter, the conversions are exact and not approximate, as can be the case with a few fringe measurement units in other areas.

This speed converter can convert between different speed units, you just need to enter a original value and select the original unit in combobox, converter will quickly calculate all the values of other speed units.

How To Use:

1. Input a valid numeric.

2. Select an original Speed unit, such as Mile/hour, Kilometer/hour , Foot/second or other.

3. Click button "Convert" to calculate.

4. The calculation results will be displayed in table.

What is Speed?

The rate of movement of something is speed.

Speed of things (living or non-living) like car, man, etc. determines the measurement how fast or slow the thing is moving.

Measurement of speed can help us to reduce the time required to complete the work in effective manner.

Speed is the rate of change in position of an object, regardless of direction of travel. Walk forward or backward at 2 meters per second, and your speed is just that: 2 m/s. Velocity is speed in the context of direction. Say you were walking backward again; your velocity is negative 2 m/s, although your speed is still positive.

For most science applications, the SI unit for speed and velocity is meters per second (m/s), although kliometers per hour (km/h) is sometimes used when measuring the speed of vehicles. The English system usually expresses speed as miles per hour (mph) or sometimes feet per second (ft/s), while marine vessels typically use knots, or nautical miles per hour.

Average speed formula

Since the main purpose of this calculator is to calculate average speed, let's take a more in-depth look at this topic. Average speed is measured in units of distance per time, and the average speed formula looks like this:

average speed = total distance / total time

Typical units are kilometers per hour (kph), miles per hour (mph), meters per second (m/s) and feet per second (ft/s). In our mph calculator the default unit is mph (kph for metric-units countries), but you can change between any of the common units.

How to Convert Units of Speed

Conversions are performed by using a conversion factor. By knowing the conversion factor, converting between units can become a simple multiplication problem:

S * C = E

Where S is our starting value, C is our conversion factor, and E is our end converted result.

To simply convert from any unit into meters per second, for example, from 5 mph, just multiply by the conversion value in the right column in the table.

5 mph * 0.44704 [ (m/s) / (mph) ] = 2.2352 m/s

To convert from m/s into units in the left column divide by the value in the right column or, multiply by the reciprocal, 1/x.

2.2352 (m/s) / 0.44704 [ (m/s) / (mph) ] = 5 mph

To convert among any units in the left column, say from A to B, you can multiply by the factor for A to convert A into meters per second then divide by the factor for B to convert out of meters per second. Or, you can find the single factor you need by dividing the A factor by the B factor.

For example, to convert from miles per hour to kilometers per hour you would multiply by 0.44704 then divide by 0.2777778. Or, multiply by 0.44704/0.27777778 = 1.6093439. So, to convert directly from mph to km/h (kph), you multiply by 1.6093439.

Why Should You Use A Speed Distance Calculator?

Speed has to do with how fast movement occurs, that is, distance in relation to time. One way of measuring the speed at which a moving object travels such as miles per hour (mph) might not be applicable. Because distance and time are important when we’re referring to motion and speed, we need to know the various units in talking about time, speed and distance.

Also, different countries have different units of measuring speed. In the US, the unit of speed is measured as miles per hour (mph), while the general SI unit is measured as kilometer per hour. One mile per hour is equal to 1.609344 kilometers per hour. Thus, you need a speed calculator because there are different units of distance; such as centimetres, feet, meters, miles, and so on. Also, because there are different units of time; such as seconds, minutes, and hours.

Average speed vs average velocity

Speed and velocity might seem to be the same thing, but they're not. Speed is a scalar quantity - it is defined by magnitude only. In simple terms, it tells you how fast an object is moving. On the other hand, velocity is a vector - it is defined not only by magnitude but also by direction. It tells you the rate at which an object changes its position.

Imagine you drove a car 100 meters forward and then 100 meters back. You would drive at a certain average speed in each direction, but you would have zero average velocity, as velocity is measured as the rate at which the position of the car changes, and, overall, the car didn't change its position. Therefore, it is enough to say that the average speed of a car was 50 mph, but when calculating velocity we would have to add direction, let's say 50 mph east.