The formula triangle
d = s × t ⇔ s = d / t ⇔ t = d / s
Cover the variable you want with your finger and read off the formula. Distance is the product of the other two; speed and time are quotients.
Internally the calculator converts your inputs to SI base units (metres, seconds), solves, then converts back to the unit you chose for the answer.
FAQ
Is "speed" the same as "velocity"?
Speed is the magnitude (just "how fast"); velocity adds direction. For straight-line travel calculations they're interchangeable. d = s × t works on average speed.
What's the conversion between km/h and m/s?
Multiply km/h by 1000/3600 = 5/18 to get m/s. So 60 km/h ≈ 16.67 m/s.
Can I use this for sound or light?
Yes — for any constant-speed problem. For accelerating bodies use kinematics formulas (v = u + at, etc.) instead.