Calculate speed, distance, or time given the other two values. Supports various common units (km, miles, m/s, km/h, mph, hours, minutes, seconds).
Speed, Distance, Time Calculator
Calculate speed, distance, or time by entering the other two known values. Select your preferred units for each measurement. Enter values in exactly two fields to calculate the third.
Enter Known Values
The Relationship: Distance = Speed × Time
This calculator is based on the fundamental formula relating distance, speed (or velocity, assuming constant velocity in one direction), and time:
$d = s \times t$
Where:
- $d$ = Distance traveled
- $s$ = Speed (constant)
- $t$ = Time elapsed
By rearranging this formula, we can solve for any of the variables if the other two are known:
- Time ($t$) = Distance ($d$) / Speed ($s$)
- Speed ($s$) = Distance ($d$) / Time ($t$)
Importance of Units
It is crucial that the units are consistent when using these formulas directly. For example, if speed is in kilometers per hour (km/h), time must be in hours to calculate distance in kilometers. This calculator handles the necessary **unit conversions** automatically based on your selections. You can input values in common units like miles, kilometers, feet, m/s, km/h, mph, seconds, minutes, or hours, and the tool will convert them internally to perform the calculation correctly.
Use Cases:
- Travel Planning: Estimate travel time based on distance and average speed.
- Calculating Distance: Determine how far you traveled given your speed and time.
- Determining Speed: Calculate the average speed required to cover a distance in a specific time.
- Physics & Science: Solving basic motion problems (assuming constant velocity).
- Sports & Fitness: Calculating pace (time per distance) or speed from race times and distances.
- Navigation & Logistics: Estimating arrival times or distances.
Examples with Step-by-Step Solutions
Click on each example to see the calculation breakdown:
Example 1: Calculate Time (km, km/h)
Problem: How long will it take to travel 500 km at an average speed of 100 km/h?
Given: Distance (d) = 500 km, Speed (s) = 100 km/h
Find: Time (t)
Steps:
- Use the formula: $t = d / s$
- Ensure units are consistent (km and km/h -> result in hours). Units are consistent.
- Calculate: $t = 500 \text{ km} / 100 \text{ km/h} = 5 \text{ hours}$
Result: It will take 5 hours.
Example 2: Calculate Time (miles, mph)
Problem: How long does it take to drive 10 miles at 30 mph?
Given: Distance (d) = 10 mi, Speed (s) = 30 mph
Find: Time (t)
Steps:
- Use the formula: $t = d / s$
- Units are consistent (miles and mph -> result in hours).
- Calculate hours: $t = 10 \text{ mi} / 30 \text{ mph} = 1/3 \text{ hours}$
- Convert hours to minutes: $(1/3 \text{ hr}) \times (60 \text{ min/hr}) = 20 \text{ minutes}$
Result: It will take 20 minutes.
Example 3: Calculate Time (m, m/s)
Problem: How many seconds to cover 1500 meters at a speed of 10 m/s?
Given: Distance (d) = 1500 m, Speed (s) = 10 m/s
Find: Time (t)
Steps:
- Use the formula: $t = d / s$
- Units are consistent (m and m/s -> result in seconds).
- Calculate: $t = 1500 \text{ m} / 10 \text{ m/s} = 150 \text{ seconds}$
Result: It will take 150 seconds (or 2 minutes, 30 seconds).
Example 4: Calculate Time (miles, ft/s)
Problem: How many minutes to travel 2 miles at a speed of 15 ft/s?
Given: Distance (d) = 2 mi, Speed (s) = 15 ft/s
Find: Time (t)
Steps:
- Use the formula: $t = d / s$
- Convert units to be consistent. Let's use feet and seconds.
- Convert distance to feet: $d = 2 \text{ mi} \times 5280 \text{ ft/mi} = 10560 \text{ ft}$
- Speed is already in ft/s: $s = 15 \text{ ft/s}$
- Calculate time in seconds: $t = 10560 \text{ ft} / 15 \text{ ft/s} = 704 \text{ seconds}$
- Convert seconds to minutes: $704 \text{ s} / 60 \text{ s/min} \approx 11.73 \text{ minutes}$
Result: It will take approximately 11.73 minutes.
Example 5: Calculate Distance (km/h, hours)
Problem: How far do you travel driving at 60 km/h for 2.5 hours?
Given: Speed (s) = 60 km/h, Time (t) = 2.5 hr
Find: Distance (d)
Steps:
- Use the formula: $d = s \times t$
- Units are consistent (km/h and hr -> result in km).
- Calculate: $d = 60 \text{ km/h} \times 2.5 \text{ hr} = 150 \text{ km}$
Result: You travel 150 kilometers.
Example 6: Calculate Distance (mph, minutes)
Problem: How many miles do you walk at 5 mph for 45 minutes?
Given: Speed (s) = 5 mph, Time (t) = 45 min
Find: Distance (d)
Steps:
- Use the formula: $d = s \times t$
- Convert units to be consistent. Let's use miles and hours.
- Convert time to hours: $t = 45 \text{ min} / 60 \text{ min/hr} = 0.75 \text{ hr}$
- Speed is already in mph: $s = 5 \text{ mph}$
- Calculate distance in miles: $d = 5 \text{ mph} \times 0.75 \text{ hr} = 3.75 \text{ miles}$
Result: You walk 3.75 miles.
Example 7: Calculate Distance (m/s, minutes)
Problem: How many meters does a cyclist cover traveling at 3 m/s for 10 minutes?
Given: Speed (s) = 3 m/s, Time (t) = 10 min
Find: Distance (d)
Steps:
- Use the formula: $d = s \times t$
- Convert units to be consistent. Let's use meters and seconds.
- Convert time to seconds: $t = 10 \text{ min} \times 60 \text{ s/min} = 600 \text{ s}$
- Speed is already in m/s: $s = 3 \text{ m/s}$
- Calculate distance in meters: $d = 3 \text{ m/s} \times 600 \text{ s} = 1800 \text{ meters}$
Result: The cyclist covers 1800 meters (or 1.8 km).
Example 8: Calculate Speed (km, hours/minutes)
Problem: What is the average speed if you travel 100 km in 1 hour and 15 minutes?
Given: Distance (d) = 100 km, Time (t) = 1 hr 15 min
Find: Speed (s)
Steps:
- Use the formula: $s = d / t$
- Convert units to be consistent. Let's find speed in km/h, so convert time to hours.
- Convert time to hours: $t = 1 \text{ hr} + (15 \text{ min} / 60 \text{ min/hr}) = 1 + 0.25 = 1.25 \text{ hours}$
- Distance is already in km: $d = 100 \text{ km}$
- Calculate speed in km/h: $s = 100 \text{ km} / 1.25 \text{ hr} = 80 \text{ km/h}$
Result: The average speed is 80 km/h.
Example 9: Calculate Speed (m, seconds)
Problem: A sprinter runs 400 meters in 50 seconds. What is their average speed in m/s?
Given: Distance (d) = 400 m, Time (t) = 50 s
Find: Speed (s)
Steps:
- Use the formula: $s = d / t$
- Units are consistent (m and s -> result in m/s).
- Calculate: $s = 400 \text{ m} / 50 \text{ s} = 8 \text{ m/s}$
Result: The average speed is 8 m/s.
Example 10: Calculate Speed (miles, minutes)
Problem: A car travels 5 miles in 10 minutes. What is the average speed in mph?
Given: Distance (d) = 5 mi, Time (t) = 10 min
Find: Speed (s)
Steps:
- Use the formula: $s = d / t$
- Convert units to be consistent. Let's find speed in mph, so convert time to hours.
- Convert time to hours: $t = 10 \text{ min} / 60 \text{ min/hr} = 1/6 \text{ hours} \approx 0.1667 \text{ hr}$
- Distance is already in miles: $d = 5 \text{ mi}$
- Calculate speed in mph: $s = 5 \text{ mi} / (1/6 \text{ hr}) = 5 \times 6 = 30 \text{ mph}$
Result: The average speed is 30 mph.
Frequently Asked Questions (FAQs)
How do I use this calculator?
Enter values and select the correct units for any **two** of the fields (Distance, Speed, Time). Leave the field you want to calculate blank. Click the "Calculate" button.
How does the calculator handle different units?
When you enter values, the calculator converts them internally to a base set of units (meters, seconds, meters/second) before performing the calculation ($d=s \times t$, $t=d/s$, or $s=d/t$). The result is then converted back to the unit you selected for the calculated field.
Does this calculator account for acceleration or stops?
No. This calculator assumes a **constant speed** over the entire duration or distance. It does not account for acceleration, deceleration, or stops during travel.
What if I enter zero for speed or time when calculating distance?
If speed or time is zero, the calculated distance will correctly be zero.
What if I enter zero for speed or time when calculating the other?
Calculating time requires dividing by speed ($t=d/s$). Calculating speed requires dividing by time ($s=d/t$). Dividing by zero is mathematically undefined. The calculator will show an error if you try to calculate speed with zero time or calculate time with zero speed (unless the distance is also zero).
