A walkthrough, end to end.
- 1
Pick which variable to solve for: speed, distance, or time.
- 2
Enter the other two with units.
- 3
See the result in your chosen unit, plus conversions to mph, km/h, m/s, and knots.
Speed equation
Speed = distance / time. Equivalently, distance = speed × time, time = distance / speed.
What you can do with this.
Trip ETA
Find arrival time at constant speed.
Average speed
From distance and elapsed time.
Running pace
Translate min/mile or min/km to mph or km/h.
Cycling speed
Compute average over a route.
Boat / aviation
Convert knots to mph or km/h.
Physics homework
Verify d = v t exercises.
Project completion
Time required at a constant pace.
Speed 2026 — what's current
Standard kinematics; calculator wins for instant unit conversion.
Frequently asked.
Distance: mi or km. Time: hours, minutes, or seconds. Speed converts between four units.
This is for average over the interval, not instantaneous.
No. All math runs in your browser.
1 knot = 1.852 km/h = 1.151 mph.