How do you calculate acceleration?

Subtract the initial velocity from the final velocity and divide by the time. 5 m/s to 25 m/s in 4 s: (25 − 5) ÷ 4 = 5 m/s². The page shows the subtraction and the division and converts to g.

What is the acceleration of a car doing 0–60 mph in 6 seconds?

60 mph is 26.8 m/s, so (26.8 − 0) ÷ 6 = 4.47 m/s², about 0.46 g, covering 80 m in those six seconds. Enter the final velocity in m/s (divide mph by 2.237).

What is deceleration?

Acceleration in the direction opposite to the motion — a negative acceleration when the forward direction is positive. Braking from 30 m/s to 0 in 3 s is −10 m/s². The magnitude is what matters for stopping distances.

How is acceleration related to force?

By Newton's second law, F = ma: the force needed is the mass times the acceleration. A 1,200 kg car accelerating at 4 m/s² needs 4,800 N from the tyres. The force calculator on this site does that step.

How do I find the final velocity from the acceleration?

Rearrange: final velocity = initial velocity + acceleration × time. Starting at 5 m/s and accelerating at 2 m/s² for 6 s ends at 5 + 12 = 17 m/s.

What is 1 g of acceleration?

9.80665 m/s², standard gravity — how fast a dropped object speeds up near the Earth's surface. A car accelerating at a steady 1 g would reach 100 km/h in 27.78 ÷ 9.80665 = 2.8 seconds.

Acceleration Calculator (Change in Velocity ÷ Time)

Average acceleration from initial and final velocity and time, in m/s² and g, with the distance covered.

Inputs

Initial velocity(m/s)

-1,000,000 m/s1,000,000 m/s

Final velocity(m/s)

-1,000,000 m/s1,000,000 m/s

Time(s)

0.001 s1,000,000,000 s

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Acceleration

4 m/s²

Working: (20 − 0) ÷ 5 = 20 ÷ 5 = 4 m/s²
In g: 0.408 g
Distance covered meanwhile: average speed × time = 10 × 5 = 50 m
Δv: 20 m/s (72.00 km/h)

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What each Acceleration input means

Initial velocity: The velocity at the start, in m/s: 0 for a standing start. Divide km/h by 3.6, or multiply mph by 0.447, to convert.
Final velocity: The velocity at the end, in m/s. Smaller than the start for braking, which gives a negative acceleration; negative if the motion reversed.
Time: The time the change took, in seconds.

Acceleration formula

a = (final velocity − initial velocity) ÷ time · distance covered = (initial + final) ÷ 2 × time (constant acceleration) · 1 g = 9.80665 m/s²

\bar{a} = \frac{v - v_0}{t}, \qquad d = \frac{v_0 + v}{2}\, t

Acceleration is how quickly velocity changes: the change in velocity divided by the time it took. A car going from rest to 20 m/s in 5 seconds accelerates at 4 m/s² — its speed rises by 4 m/s every second. The sign follows the change: slowing down is a negative acceleration (deceleration), and a velocity that reverses direction gives a change larger than either speed. Because velocity changes steadily under constant acceleration, the average velocity is simply the mean of the start and end values, and multiplying that by the time gives the distance covered — 50 m for the car above. The page also expresses the acceleration in g, the acceleration of gravity, which is how cars, rockets and roller-coasters are usually compared.

Acceleration worked example

From rest to 20 m/s (72 km/h) in 5 seconds: (20 − 0) ÷ 5 = 4 m/s², which is 0.41 g. The average velocity during the run is (0 + 20) ÷ 2 = 10 m/s, so the car covers 10 × 5 = 50 m. Braking from 20 m/s to a stop in 2 seconds would be (0 − 20) ÷ 2 = −10 m/s², just over 1 g.

More Acceleration examples

A car doing 0–100 km/h (27.78 m/s) in 8 seconds: 27.78 ÷ 8 = 3.4725 m/s², about 0.35 g, and it covers 111 m while doing it.

Braking from 25 m/s (90 km/h) to a stop in 3 seconds: (0 − 25) ÷ 3 = −8.3333 m/s², about 0.85 g of deceleration, over a stopping distance of 37.5 m.

Where the Acceleration calculator can give the wrong answer

This is average acceleration. If the acceleration varied — a car changing gear, a sprinter's first strides — the figure is the overall average, and the distance line assumes it was constant.
Direction matters. Going from +10 m/s to −10 m/s (a bounce) is a change of 20 m/s, not 0; keep one direction positive and the other negative.
Units: metres per second for velocity and seconds for time. Velocities in km/h must be divided by 3.6 first, or the acceleration comes out 3.6 times too large.
Sustained accelerations above a few g are dangerous to people; 4 m/s² is brisk for a car, and a 0–100 km/h time of 5 s is 5.6 m/s².
Time must be positive; zero time with a change in velocity would be infinite acceleration.

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Acceleration reference table

0–100 km/h times as an average acceleration
0–100 km/h time	Acceleration	In g
3 s	9.26 m/s²	0.94 g
5 s	5.56 m/s²	0.57 g
8 s	3.47 m/s²	0.35 g
10 s	2.78 m/s²	0.28 g
15 s	1.85 m/s²	0.19 g

Source: Arithmetic: 100 km/h = 27.78 m/s, divided by the time; 1 g = 9.80665 m/s² (standard gravity)

Acceleration FAQ

: Subtract the initial velocity from the final velocity and divide by the time. 5 m/s to 25 m/s in 4 s: (25 − 5) ÷ 4 = 5 m/s². The page shows the subtraction and the division and converts to g.
: 60 mph is 26.8 m/s, so (26.8 − 0) ÷ 6 = 4.47 m/s², about 0.46 g, covering 80 m in those six seconds. Enter the final velocity in m/s (divide mph by 2.237).
: Acceleration in the direction opposite to the motion — a negative acceleration when the forward direction is positive. Braking from 30 m/s to 0 in 3 s is −10 m/s². The magnitude is what matters for stopping distances.
: By Newton's second law, F = ma: the force needed is the mass times the acceleration. A 1,200 kg car accelerating at 4 m/s² needs 4,800 N from the tyres. The force calculator on this site does that step.
: Rearrange: final velocity = initial velocity + acceleration × time. Starting at 5 m/s and accelerating at 2 m/s² for 6 s ends at 5 + 12 = 17 m/s.
: 9.80665 m/s², standard gravity — how fast a dropped object speeds up near the Earth's surface. A car accelerating at a steady 1 g would reach 100 km/h in 27.78 ÷ 9.80665 = 2.8 seconds.