Speed Calculator

Calculate speed, distance, or time. Convert between mph, km/h, m/s, and more. Free speed distance time calculator with unit conversions.

Speed

Speed

66.67 mph

mph66.67
km/h107.29
m/s29.80

What would you like to calculate?

Enter Values

Time

Results

Average Speed

66.67 mph

mph

66.67

km/h

107.29

m/s

29.80

knots

57.93

Speed-Distance-Time Formula

Speed

= Distance ÷ Time

Distance

= Speed × Time

Time

= Distance ÷ Speed

Speed Conversion Reference

mphkm/hm/sknots
1016.14.58.7
2540.211.221.7
5080.522.443.4
6096.626.852.1
70112.731.360.8
100160.944.786.9
120193.153.6104.3

Frequently Asked Questions

Speed = Distance ÷ Time. Divide the distance traveled by the time it took. For example, if you travel 150 miles in 3 hours, your average speed is 150 ÷ 3 = 50 mph. Make sure distance and time units match (miles with hours for mph).
Multiply mph by 1.60934 to get km/h. Alternatively, divide km/h by 1.60934 to get mph. Quick estimate: multiply mph by 1.6. Example: 60 mph × 1.6 = 96 km/h (actual: 96.56 km/h).
Distance = Speed × Time. Multiply your speed by the time traveled. Example: traveling at 65 mph for 4.5 hours covers 65 × 4.5 = 292.5 miles. Ensure your units are consistent.
Time = Distance ÷ Speed. Divide the distance by your average speed. Example: a 200-mile trip at 60 mph takes 200 ÷ 60 = 3.33 hours (3 hours 20 minutes). Account for stops and traffic.
A knot is a nautical unit of speed equal to one nautical mile per hour, or approximately 1.15 mph (1.85 km/h). It's used in maritime and aviation contexts. Named for the knots on ropes used to measure ship speed historically.