Mile per Second (mi/s)

What Is Mile per Second (mi/s)?

Mile per second is a unit that measures speed. It tells you how many miles an object moves in exactly one second. Because one second is very short, a speed of one mile per second is extremely fast and is much faster than any car or plane. This unit is mainly used in science, space studies, and for very high speeds.

Definition

One mile per second means an object travels a distance of one mile during a time of one second.

In numbers:

• 1 mile per second = 1 mile every second
• 1 mile per second = 3,600 miles per hour
• 1 mile per second ≈ 1,609.344 meters per second
• 1 mile per second ≈ 5,793.64 kilometers per hour

This speed is far beyond normal everyday speeds and is usually used for very fast objects like rockets, meteors, or in math and physics problems.

History / Origin

The unit mile per second was not invented all at once. It comes from two older ideas.

• Mile grew from old Roman and English distance units. Over time, the mile became fixed as 1,609.344 meters in most English speaking countries.
• Second comes from ancient time keeping, where a day was split into hours, minutes, and seconds. Today it is defined very exactly using atomic clocks.

When scientists began to study motion and speed, they started to combine distance units and time units. So, mile per second simply joins the old mile with the second to create a way to measure very high speeds. It never became common in daily life, because mile per hour and meter per second are easier to use for normal travel.

Symbol & Abbreviation

There are a few ways to write mile per second.

• Full name: mile per second
• Common symbol: mi/s
• Sometimes also seen: mile/s or mps in informal writing

The clearest and safest short form in science is mi/s, because it clearly shows miles and seconds, and it reduces confusion with meter per second, which uses the symbol m/s.

Current Use Around the World

Mile per second is not a common everyday unit. Most countries use kilometers per hour or meters per second for speed, and places that use miles usually prefer miles per hour.

Mile per second is mainly seen in.

• Space science and astronomy, to describe very fast objects, like meteors or spacecraft in some examples.
• Physics problems, where very high speeds are easier to show using mi/s.
• Educational examples, when teachers want to show how fast something is compared to cars or planes.

In real work, experts more often use kilometers per second or meters per second, even for very high speeds.

Example Conversions

Here are some useful conversions for one mile per second.

• 1 mi/s = 1 mile per second
• 1 mi/s = 3,600 miles per hour (mph)
• 1 mi/s ≈ 5,793.64 kilometers per hour (km/h)
• 1 mi/s ≈ 1,609.344 meters per second (m/s)
• 1 mi/s = 5,280 feet per second (ft/s)

Some comparison ideas.

• A family car on a highway is about 60 mph. That is 1/60 of 1 mi/s.
• Commercial jets fly around 500 to 600 mph. That is still far slower than 1 mi/s.
• The speed of sound in air near sea level is about 343 m/s. One mi/s is about 4.7 times faster than this.

Simple step by step example. Convert 2 mi/s to mph.

1. 1 mi/s = 3,600 mph
2. 2 mi/s = 2 × 3,600 mph = 7,200 mph

Convert 0.5 mi/s to m/s.

1. 1 mi/s ≈ 1,609.344 m/s
2. 0.5 mi/s = 0.5 × 1,609.344 ≈ 804.672 m/s

Related Units

These units are closely related to mile per second and are often used instead.

• Mile per hour (mph) measures miles traveled in one hour. Used for road speeds in the United States and some other places.
• Meter per second (m/s) is the main speed unit in science in the metric system. It shows how many meters are traveled in one second.
• Kilometer per hour (km/h) is the common road speed unit in most countries that use the metric system.
• Kilometer per second (km/s) is used for very high speeds in space and astronomy, like the motion of planets and stars.
• Foot per second (ft/s) uses feet and seconds. Sometimes used in ballistics and engineering.
• Knot (kt) is a speed unit used in ships and airplanes. One knot is one nautical mile per hour.

FAQs

Is mile per second faster than mile per hour?

Yes. Mile per second is much faster. One mi/s equals 3,600 mph. That means something moving at 1 mi/s would cover in one second what a car at 60 mph travels in one minute.

Why is mile per second not used for cars or planes?

Cars and planes are not nearly fast enough to make mile per second easy to work with. Their speeds are usually below 1,000 mph. Using mile per second would give very small decimal numbers, which is harder to read. Mile per hour or kilometer per hour is more practical.

Where would someone actually use mi/s?

You might see mi/s in.

• Science textbooks and homework questions
• Articles that try to explain space or meteor speeds to readers who know miles better than kilometers
• Some technical or military discussions about very fast projectiles or missiles

How do I convert mi/s to m/s or km/h?

Use these rules.

• To change mi/s to m/s, multiply by 1,609.344.
• To change mi/s to km/h, multiply by 5,793.64.
• To change mi/s to mph, multiply by 3,600.

Example. 0.2 mi/s × 3,600 = 720 mph.

Is mi/s based on the same mile used in road signs?

Yes. Mile per second uses the standard statute mile, the same mile you see on road signs in the United States and the United Kingdom, which is 1,609.344 meters long.

Is mi/s the same as m/s?

No, they are very different. mi/s means mile per second and uses miles. m/s means meter per second and uses meters. Because one mile is much longer than one meter, 1 mi/s is much faster than 1 m/s. Always check the letters carefully.