Acceleration Calculator
Find the acceleration, the velocity change or the time taken from a = Δv ÷ Δt.
What is Acceleration?
Acceleration is how quickly velocity changes, measured in metres per second squared. One m/s² means the velocity grows by one metre per second every second. Because velocity has a direction, acceleration can also mean slowing down or turning — a car braking hard and a car pulling away are both accelerating.
How it works
a = Δv ÷ Δt, where Δv is the final velocity minus the initial one. A negative change gives a negative acceleration, which is deceleration in the direction of travel. Accelerations can be read as multiples of g (9.80665 m/s²) so a result like '3.2 g' is immediately comparable to an everyday landmark.
- Enter what you know. Every field recalculates as you type — there is no submit button. Leave the quantity you want blank and the page solves for it.
- Read the answer and the working. The result appears above the fold; underneath it is the formula with your numbers substituted, so the arithmetic can be checked rather than trusted.
- Check the units and the size. Units are shown on every value and selectable per field, so a result in kJ, kPa or km/h is converted rather than assumed. Sanity-check the magnitude against a known landmark such as 1 g/cm³ for water.
Examples
A textbook problem with a known answer
Every tool here is checked against standard example problems — the molar mass of C6H12O6 is 180.16 g/mol, and free fall from 20 m takes about 2.02 s at g = 9.8 m/s².
A result you want to reason backwards from
Leave the quantity you already know blank instead: given the final answer, most tools recover the starting value — the mass needed for a target concentration, or the height a fall must have had.
Common mistakes
Forgetting that a formula is only as good as its subscripts
H2O and H2O2 are different compounds. The formula field shows its parse — element by element — so a mis-typed subscript is visible before it reaches the arithmetic.
Mixing units in the middle of a calculation
The most common source of a wrong answer is a value in grams next to a formula expecting kilograms, or Celsius next to a gas constant expecting kelvin. This category converts on the way in and labels what it used.
Frequently asked questions
How do I find acceleration from a standing start?
Δv is just the final velocity, since the initial velocity is zero. A car reaching 100 km/h (27.8 m/s) in 8 seconds accelerates at 3.47 m/s².
Can acceleration be negative?
Yes, and a negative value simply means the change in velocity is opposite to the direction you called positive — slowing down if the object was moving forward.
What is a g-force?
An acceleration expressed as a multiple of Earth's surface gravity, 9.80665 m/s². A roller coaster pulling 3 g is accelerating at about 29.4 m/s².