The Fundamental Relationship: Speed, Distance, and Time

Speed, distance, and time are the cornerstones of motion. Understanding their relationship is essential not just for physics class, but for everyday activities like planning a road trip, timing a run, or estimating arrival times. This calculator simplifies the process by allowing you to solve for any one of these three variables if you know the other two.

The Speed, Distance, Time Formula

The relationship is defined by a simple and elegant set of formulas:

• To find Speed: Speed = Distance / Time
• To find Distance: Distance = Speed × Time
• To find Time: Time = Distance / Speed

How to Use the Calculator

1. Select what to calculate: Use the selector at the top to choose whether you're solving for Speed, Distance, or Time. The disabled field will become your result.
2. Enter the known values: Fill in the numbers for the two variables you have. For example, if you are calculating speed, you will enter the distance and the time.
3. Choose your units: Select the correct units for each value from the dropdown menus (e.g., miles, hours, mph).
4. Calculate: Click the button to see the result. The answer will be displayed in its primary units, with helpful conversions to other common units shown below.

Practical Applications

• Travel Planning: Estimate your arrival time for a road trip by entering the distance and your average driving speed. You can also calculate the required speed to arrive by a certain time. For precise time calculations involving start/end times, use our Time Calculator.
• Running & Fitness: Calculate your average pace (speed) by entering the distance you ran and the time it took.
• Science & Engineering: A fundamental tool for any problem involving motion, from simple physics homework to complex engineering challenges.
• Project Management: Estimate how long a task will take (time) by knowing the work rate (speed) and the amount of work (distance). For calculations spanning multiple days, our Day Counter can be useful.