Speed Calculator
Calculate speed, distance, or time using the speed-distance-time relationship and convert between units.
A speed calculator solves for speed, distance, or time using the fundamental motion formula, with automatic unit conversions across imperial and metric systems.
Examples
Calculate speed
Calculate time
Frequently Asked Questions
What is the difference between mph and knots?
How do I convert minutes to hours?
Quick Tips
- •Time is entered in hours. Use decimals for partial hours (e.g. 1.5 = 1h 30m).
- •The calculator converts between all speed units automatically.
- •Knots are commonly used in aviation and marine navigation.
A speed calculator solves for speed, distance, or time using the fundamental motion formula, with automatic unit conversions across imperial and metric systems.
How to Use This Calculator
Select what you want to solve for (speed, distance, or time), enter the known values, and choose appropriate units. The calculator uses the formula v = d/t and its rearrangements.
Understanding the Formula
Speed = Distance / Time (v = d/t). Distance = Speed x Time (d = v*t). Time = Distance / Speed (t = d/v). All conversions go through meters and seconds internally for accuracy.
Examples
Calculate speed
A car travels 150 miles in 2.5 hours. Speed = 150 / 2.5 = 60 mph.
Calculate time
A plane flies 500 km at 800 kph. Time = 500 / 800 = 0.625 hours = 37 minutes 30 seconds.
Frequently Asked Questions
What is the difference between mph and knots?
1 knot = 1 nautical mile per hour = 1.15078 mph. Knots are used in aviation and sailing because nautical miles map directly to degrees of latitude.
How do I convert minutes to hours?
Divide minutes by 60. For example, 45 minutes = 45/60 = 0.75 hours.
Assumptions & Limitations
- Assumes constant speed for the entire duration; does not account for acceleration or deceleration.
- Time is entered in hours; convert minutes to decimal hours for accurate results.