What is acceleration and how to calculate it
Updated on June 30, 2026 · by Rafael Rossi
Acceleration measures how fast velocity changes. If speed rises, acceleration is positive; if it falls (braking), it's negative.
The formula
a = (v_final − v_initial) ÷ time, in meters per second squared (m/s²).
What m/s² means
It's gaining 1 m/s of speed every second. A car from 0 to 100 km/h (~27.8 m/s) in 10 s accelerates at ~2.8 m/s².
Distance with constant acceleration
With constant acceleration, distance is the average velocity × time: d = (v_i + v_f)/2 · t, or d = v_i·t + ½·a·t².
Step-by-step example
A car starts from rest and accelerates at 3 m/s² for 5 s:
- Final speed: 0 + 3 × 5 = 15 m/s (54 km/h)
- Distance: ½ × 3 × 5² = 37.5 m
FAQ
Are acceleration and velocity the same? No. Velocity is how far you move per second; acceleration is how much velocity changes per second. You can have high velocity with zero acceleration (constant speed).
What is gravity in m/s²? The free-fall acceleration: ~9.8 m/s² on Earth. A dropped object gains 9.8 m/s of speed every second.