The acceleration calculator uses the kinematic formula a = (v − u) / t to find acceleration from initial velocity, final velocity, and time. Enter any three values to solve for the fourth. Supports both m/s² (metric) and ft/s² (imperial) units for physics coursework and real-world problems.
Acceleration Calculator
Select what to solve for:
How to Use the Acceleration Calculator
This acceleration calculator solves for any variable in the kinematic acceleration equation a = (v − u) / t. Whether you need acceleration, initial or final velocity, or time, select the unknown and fill in the rest.
Step 1: Select the Unknown Variable
Choose what you want to calculate: Acceleration (a), Initial Velocity (u), Final Velocity (v), or Time (t). The selected field becomes the output — it will be grayed out and solved automatically.
Step 2: Choose Metric or Imperial
Toggle between Metric (m/s, m/s²) and Imperial (ft/s, ft/s²). All velocity values convert automatically when you switch systems.
Step 3: Enter Known Values
Fill in the three known values. For example, if a car accelerates from rest (u = 0 m/s) to 27.8 m/s (100 km/h) in 10 seconds, the acceleration is a = (27.8 − 0) / 10 = 2.78 m/s².
Negative Acceleration (Deceleration)
If the final velocity is less than the initial velocity, you'll get a negative acceleration — this is deceleration (braking). A car braking from 30 m/s to rest in 6 seconds has acceleration a = (0 − 30) / 6 = −5 m/s².
Real-World Examples
Gravity: Near Earth's surface, free-fall acceleration is 9.81 m/s² (32.2 ft/s²). An object dropped from rest reaches about 88.3 m/s (290 ft/s) after 9 seconds.
Sports: A sprinter accelerates from 0 to 10 m/s in 2 seconds — acceleration = 5 m/s². Compare this to a car's 0–60 mph (0–26.8 m/s) time of 4 seconds: a = 6.7 m/s².
FAQ
What is the acceleration formula?
The standard kinematic formula is a = (v - u) / t, where a is acceleration, v is final velocity, u is initial velocity, and t is time. If you know distance instead of final velocity, use a = 2(s - ut) / t², where s is distance traveled.
What is the difference between acceleration and deceleration?
Deceleration is simply negative acceleration — the object is slowing down rather than speeding up. In physics, both are described by the same formula; deceleration just has a negative value when the force opposes motion. This calculator handles both positive and negative acceleration.
Is this calculator free?
Yes, completely free with no signup required. All calculations happen in your browser.
Is my data private?
Yes. Everything runs locally in your browser. No data is sent to any server.
What units does this support?
Metric: m/s for velocity, seconds for time, m/s² for acceleration. Imperial: ft/s for velocity, ft/s² for acceleration. You can toggle between unit systems using the switch at the top of the tool.