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Physics formula

How to calculate acceleration

Acceleration measures how quickly velocity changes.

See the formulaOpen calculator
Direct answer
Formula
a = (v - v0) / t

Use the table below to match each symbol with the right input. Keep units consistent before you start.

Acceleration formula
Start here when you only need the equation and variable names.
Formula
a = (v - v0) / t

Acceleration measures how quickly velocity changes.

Variable meanings
Check each symbol, meaning, and unit before you calculate.
SymbolNameDescriptionUnit
aAccelerationRate of velocity change.m/s^2
vFinal velocityVelocity at the end.m/s
v0Initial velocityVelocity at the start.m/s
tTimeElapsed time.s
When to use this formula
Check that your situation matches the formula before you trust the result.
  • Acceleration fits motion that changes at a steady rate over a known time interval.
Step-by-step method
Follow these steps when you are solving it by hand.
  1. 1Use the same velocity units for initial and final velocity.
  2. 2Subtract initial velocity from final velocity.
  3. 3Divide by elapsed time.
  4. 4Keep the sign to show speeding up or slowing down.
Examples
These sample numbers show the order of operations and units.
Speeding up
v0
0 m/s
v
30 m/s
t
6 s
  1. 1.a = (30 - 0) / 6
  2. 2.a = 5 m/s^2
Result
The acceleration is 5 m/s^2.
Slowing down
v0
20 m/s
v
5 m/s
t
3 s
  1. 1.a = (5 - 20) / 3
  2. 2.a = -5 m/s^2
Result
The acceleration is -5 m/s^2.
Mistakes to avoid
Small input or unit errors can change the answer a lot.
  • Mixing metric and imperial units before solving the acceleration formula.
  • Forgetting squared units such as m^2, m/s^2, or velocity squared.
  • Dropping negative signs when direction matters.
  • Rounding measured values too early in the calculation.
Open the Acceleration Calculator
Open the calculator for the answer without rewriting the formula.

Enter your values in the related calculator, then compare the output with the hand method above.

Open Acceleration Calculator
FAQs
Short answers for common formula questions.
Can I calculate Acceleration by hand?

Yes. Write the units next to each value, convert rates or measurements first, and round only the final answer.

Why does my Acceleration result differ from another calculator?

Most differences come from rounding, unit conversions, rate timing, or a slightly different version of the formula.

When is the Acceleration Calculator better than hand math?

Open the Acceleration Calculator to check several scenarios or skip the hand arithmetic.