Velocity Formula Explained

This reference explains the Velocity formula used by our free Velocity Calculator. Use it to understand variables, units, and common mistakes before you calculate.

The formula

v = Δx ÷ Δt (displacement over time)

Variables and units

• Δx — Displacement (change in position) (m, km, etc.)
• Δt — Time interval (s, h, etc.)
• v — Velocity (m/s, km/h, etc.)

Worked example

Inputs: Object moves 150 m east in 12 s

1. v = Δx / Δt = 150 / 12 = 12.5 m/s east

Result: Velocity = 12.5 m/s east (includes direction)

When to use this formula

Use this formula when you need a quick velocity estimate with values you already know. Our Velocity Calculator applies the same relationship automatically so you can verify handwritten work.

Common mistakes

• Using total distance instead of displacement
• Ignoring direction when velocity (not speed) is asked
• Unit mismatch (km with seconds without converting)

Frequently asked questions