About the Speed, Distance & Time Calculator
The relationship between speed, distance, and time is one of the most fundamental formulas in physics and everyday travel planning, but rearranging it to solve for whichever variable is unknown trips people up more often than the math itself warrants.
This calculator lets you select which value you're solving for — speed, distance, or time — and enter the other two known values, handling the algebra automatically rather than requiring you to remember which variables to divide or multiply.
Frequently Asked Questions
What's the formula this calculator is based on?
It uses the standard physics relationship: distance = speed × time. Rearranged, speed = distance ÷ time, and time = distance ÷ speed.
Does this account for stops or breaks during a trip?
No — it calculates based on constant average speed. For a road trip with breaks, you'd want to use your total driving time (excluding stops) rather than total elapsed trip time for an accurate speed estimate.
Can I use this for units other than miles and mph?
The calculator's math works for any consistent unit pair (e.g., kilometers and km/h) — just be sure distance and speed use matching units.