What is the difference between speed and velocity?

Speed is a scalar quantity - it has magnitude only (e.g., 60 km/h). Velocity is a vector quantity - it has both magnitude and direction (e.g., 60 km/h northward). In everyday usage, the terms are often used interchangeably, but in physics, the distinction is important.

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

To convert km/h to m/s, divide by 3.6. For example, 72 km/h ÷ 3.6 = 20 m/s. To convert m/s to km/h, multiply by 3.6. This conversion is frequently needed in physics problems.

What is average speed vs instantaneous speed?

Average speed is the total distance divided by total time for a journey. Instantaneous speed is the speed at a specific moment in time (what a speedometer shows). Average speed can be calculated from start and end points; instantaneous speed requires calculus (the derivative of position with respect to time).

How long does it take to travel 100 km at 80 km/h?

Time = Distance ÷ Speed = 100 ÷ 80 = 1.25 hours = 1 hour 15 minutes. You can verify this with the calculator by entering distance = 100 km and speed = 80 km/h.

What is the speed of light?

The speed of light in a vacuum is approximately 299,792,458 m/s (about 300,000 km/s or 186,000 miles per second). It is denoted by the letter c and is a fundamental constant of nature. Nothing with mass can travel at or faster than the speed of light.

Science

Speed, Distance & Time Calculator

Calculate speed, distance, or time using the fundamental physics relationship. Supports multiple units including km/h, mph, and m/s.

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Speed = Distance / Time | Distance = Speed × Time | Time = Distance / Speed

Variables

vSpeed (velocity)

dDistance

tTime

Explanation

The speed-distance-time relationship is one of the most fundamental equations in physics. Speed is the rate of change of distance with respect to time. Given any two of the three quantities, the third can always be calculated.

What is the Speed, Distance & Time Calculator?

The relationship between speed, distance, and time is one of the most fundamental concepts in physics and everyday life. Whether you are planning a road trip, analyzing athletic performance, solving physics problems, or calculating fuel consumption, this relationship appears constantly. The speed-distance-time calculator makes these calculations instant and error-free.

How to Use This Calculator

Select two known quantities (any combination of speed, distance, and time), enter their values with appropriate units, and the calculator solves for the third quantity. Results are provided in multiple units for convenience.

Worked Examples

Average speed over 150 km in 2 hours

A road trip covering 150 km that took 2 hours including stops.

Speed = distance ÷ time: 150 ÷ 2 = 75 km/h
In mph: ≈ 46.6 mph

Average speed 75 km/h (about 46.6 mph).

This is average speed for the whole trip — your speedometer reading at any moment can be much higher or lower.

How long to drive 100 km at 80 km/h?

Known speed and distance — solve for time.

Time = distance ÷ speed: 100 ÷ 80 = 1.25 hours
In minutes: 1 hour 15 minutes

The trip takes 1 hour 15 minutes.

Why Use MyCalculatorsHub's Speed / Distance Calculator?

This calculator supports a wide range of units - kilometers, miles, meters, hours, minutes, seconds, km/h, mph, and m/s - and handles all conversions automatically. This eliminates the most common source of errors in speed-distance-time problems.

Common Mistakes to Avoid

The most common mistake is using inconsistent units - for example, mixing kilometers with hours in one part of the calculation and miles with minutes in another. Always ensure your units are compatible, or use this calculator to handle conversions automatically.