Calculate speed, distance, or time using the formula: speed = distance/time
then enter the known values below
speed = distance ÷ time
The relationship between speed, distance, and time is one of the most fundamental concepts in physics and everyday life. These three quantities are connected by a simple but powerful formula.
speed = distance ÷ time
or equivalently: s = d/t
From this fundamental equation, we can derive two other important formulas:
The speed triangle is a visual way to remember the relationship between speed, distance, and time. It helps you quickly determine which formula to use.
How to use:
To find Speed:
Speed = Distance ÷ Time
Cover S, see D/T
To find Distance:
Distance = Speed × Time
Cover D, see S × T
To find Time:
Time = Distance ÷ Speed
Cover T, see D/S
Problem: A car travels 165 miles in 3 hours. What is its average speed?
Given:
Distance = 165 miles
Time = 3 hours
Formula: speed = distance ÷ time
Calculation:
speed = 165 mi ÷ 3 hr
speed = 55 miles per hour (mph)
Problem: A train travels at 80 km/h for 2.5 hours. How far does it travel?
Given:
Speed = 80 km/h
Time = 2.5 hours
Formula: distance = speed × time
Calculation:
distance = 80 km/h × 2.5 hr
distance = 200 kilometers
Problem: How long will it take to drive 300 miles at 60 mph?
Given:
Distance = 300 miles
Speed = 60 mph
Formula: time = distance ÷ speed
Calculation:
time = 300 mi ÷ 60 mph
time = 5 hours
Calculate how long your road trip will take, or determine if you need to speed up to arrive on time. Essential for planning vacation drives, daily commutes, and delivery schedules.
Track running pace, cycling speed, or swimming velocity. Athletes use these calculations to monitor performance, set training goals, and analyze race results.
Foundation for understanding motion, velocity, and acceleration. Used in mechanics, astronomy, and any field involving moving objects or energy transfer.
Pilots and sailors use speed-distance-time calculations for flight planning, fuel consumption estimates, and arrival time predictions. Critical for safe and efficient navigation.
Average speed is the total distance divided by total time, while instantaneous speed is the speed at a specific moment. The formulas in this calculator give average speed over the journey.
Speed is a scalar quantity (magnitude only), while velocity is a vector quantity (magnitude and direction). For practical purposes in this calculator, we treat them the same.
These formulas assume constant speed. If speed varies during the journey, the calculated speed represents the average speed over the entire trip.
Always ensure your units are consistent. If distance is in miles and time in hours, speed will be in miles per hour (mph). Our calculator handles unit conversions automatically.
The formula for speed is: speed = distance ÷ time. This means speed equals the distance traveled divided by the time taken. For example, if you travel 100 miles in 2 hours, your speed is 100 ÷ 2 = 50 mph.
To calculate travel time, use the formula: time = distance ÷ speed. Divide the total distance you need to travel by your average speed. For instance, a 300-mile trip at 60 mph will take 300 ÷ 60 = 5 hours.
MPH (miles per hour) and km/h (kilometers per hour) are different units for measuring speed. 1 mile = 1.609 kilometers, so 60 mph ≈ 97 km/h. The United States primarily uses mph, while most other countries use km/h.
Yes! For running, enter your distance (e.g., 5 km) and time (e.g., 25 minutes), then select "Solve for Speed" to get your pace. You can convert between different units like min/km or min/mile.
Average speed is the total distance traveled divided by the total time taken, including stops and slowdowns. It differs from your speedometer reading, which shows instantaneous speed at any given moment.
Common conversions: 1 mph = 1.609 km/h, 1 mph = 0.447 m/s, 1 m/s = 3.6 km/h. Our calculator automatically converts between units, so you can input in any unit and get results in your preferred unit.
If your speed changes during the journey (which is common in real driving), the calculator will give you the average speed. This is still useful for planning purposes, even though you may go faster or slower at different points.
Yes, but keep in mind this calculator measures average speed along the path traveled (distance), not displacement. For circular motion, the distance is the circumference of the circle, even though the displacement might be zero.