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⚡ Speed Calculator

Calculate speed from distance and time. Works for running, cycling, driving, and swimming.

Enter Your Values

Distance covered (in your chosen unit)
Time taken in hours

How to Calculate Speed from Distance and Time

Speed is calculated by dividing distance by time. In SI units: Speed (m/s) = Distance (m) ÷ Time (s). For practical daily use: Speed (km/h) = Distance (km) ÷ Time (hours). If you drove 300 km in 3 hours, your average speed was 100 km/h. This calculator accepts distance and time in your chosen units and outputs speed accordingly.

Average speed versus instantaneous speed: this calculator gives you average speed over the full distance and time you enter. Instantaneous speed (what your speedometer shows) fluctuates moment to moment. If you drove 300 km over 3 hours but spent 30 minutes stationary at a rest stop, your average speed over the full duration (including stop time) is 100 km/h, but your average speed while actually moving would be higher.

speed limits: urban areas are typically 60 km/h, suburban residential roads 40 km/h, rural roads 100 km/h, and freeways 120 km/h. The speed limit on any specific road is shown on white circular signs. Note that average speed camera networks (in use on some national routes) calculate your average speed between two points — not just your speed at a single location — so maintaining consistent legal speeds matters throughout a journey.

Trip time estimation: rearranging the speed formula gives time = distance ÷ speed. If you need to drive 450 km on a freeway averaging 110 km/h, your estimated drive time is 450 ÷ 110 = 4.09 hours, or approximately 4 hours and 5 minutes excluding stops. This is useful for planning fuel stops, arrival times, and overnight routes.

For running and cycling, this calculator complements the Pace Calculator on CalForge. Speed in km/h and pace in min/km are reciprocals of each other — a pace of 6:00 min/km equals a speed of 10 km/h (60 ÷ 6).

How to Calculate Speed, Distance, and Time

The three fundamental relationships: Speed = Distance ÷ Time. Distance = Speed × Time. Time = Distance ÷ Speed. These are used for travel planning, athletics, physics problems, and any situation involving motion.

Ensure consistent units before calculating. Mixing km/h and metres, or mph and feet, produces incorrect results. Convert everything to the same unit first: either all metric (km, km/h, hours) or all imperial (miles, mph, hours).

Frequently Asked Questions

How do I calculate average speed? +
Average speed = total distance ÷ total time. Example: you drive 300km in 3.5 hours — average speed = 300 ÷ 3.5 = 85.7 km/h. Note: average speed is not the average of two different speeds unless equal distances were covered at each speed.
How do I convert km/h to mph? +
Multiply km/h by 0.621371. Example: 100 km/h = 62.1 mph. To convert mph to km/h, multiply by 1.60934. Quick mental check: 80 km/h ≈ 50 mph; 100 km/h ≈ 62 mph; 120 km/h ≈ 75 mph.
How long does it take to travel a specific distance? +
Time = Distance ÷ Speed. Example: at 100 km/h, how long to cover 250 km? 250 ÷ 100 = 2.5 hours (2 hours 30 minutes). For road trips, add 15-20% to the driving time for stops, traffic, and rest breaks.