Acceleration measures how quickly an object’s velocity changes. This free calculator solves the constant-acceleration kinematics relationship for any one unknown — acceleration, initial velocity, final velocity, or elapsed time — making it handy for physics homework, engineering estimates, and motion problems. Pick what you want to find, enter the known values in SI units, and the answer appears instantly.
How it works
The core equation is average acceleration:
a = (v_f − v_i) ÷ t
where v_i is the initial velocity, v_f is the final velocity, and t is the time taken. The tool rearranges this single relationship to solve for whichever quantity you leave unknown:
- Acceleration: a = (v_f − v_i) ÷ t
- Final velocity: v_f = v_i + a·t
- Initial velocity: v_i = v_f − a·t
- Time: t = (v_f − v_i) ÷ a
With velocity in metres per second (m/s) and time in seconds (s), acceleration comes out in metres per second squared (m/s²). A negative result means deceleration — the object is slowing down.
Example
A car speeds up from rest to 20 m/s over 10 seconds. Solving for acceleration:
a = (20 − 0) ÷ 10 = 2 m/s²
That means the car gains 2 m/s of speed every second.
| Quantity | Symbol | Unit |
|---|---|---|
| Initial velocity | v_i | m/s |
| Final velocity | v_f | m/s |
| Time | t | s |
| Acceleration | a | m/s² |
All calculations run locally in your browser — nothing is uploaded.