Example 1
From a standstill to 97 km/h (26.8 m/s) in 4.5 s.
Acceleration calculator
Enter a speed change and a time. The calculator computes mean a = Δv/t. From 0 to 27.8 m/s in 8 s you get about 3.47 m/s², the order of a compact car’s first 100 km/h.
Result
Speed change Δv (m/s) and Time (s). Acceleration shows up here.
How it works
Acceleration says how fast speed changes: a = Δv/t. From 0 to 100 km/h, which is 27.8 m/s, in 8 s you get about 3.47 m/s². The Δv field wants meters per second. One hundred in the field is 100 m/s, not a speedo hundred. From 0 to 27.8 m/s in 10 s is 2.78 m/s². From 0 to 13.9 m/s in 8 s is about 1.74 m/s². From 0 to 11.1 m/s in 12 s is about 0.93 m/s².
Time is in seconds. The result is in m/s². That is mean a over the t in the field, not instantaneous a from a chart. The US switch relabels empty fields; it does not rewrite a typed number. A comma and a period are the same Δv: 27,8 and 27.8. A minute is 60 s, not 1.
Time must be positive. Zero seconds does not divide. Typed 0 in Δv gives 0 m/s²: speed did not change. Δv on this page is a positive change. Braking lives on decelerated motion, not as a minus here. Both fields need a number before 3.47 can appear.
Distance at constant a is on the neighbouring page: s = v₀t + ½at². F = m·a too: here you have a, there you multiply by mass. This calculator stops at m/s². Convert 100 km/h to 27.8 m/s yourself before you fill the first field.
The 27.8 and 8 example fills after you click the button. From 0 to 10 m/s in 2 s is 5 m/s², the first meters of a sprint. From 26.8 m/s in 4.5 s is about 6.0 m/s², a quicker first hundred on the English page.
Type 27.8 and 8, click Calculate, and match about 3.47 m/s². The header symbol does not speed up seconds. Treat the result as mean a over those 8 s, not as a moment on the pedal.
You know a and want distance and final speed: accelerated motion.
How to use
- In the first field enter Δv in m/s. 100 km/h is 27.8 m/s, not 100. 50 km/h is about 13.9 m/s. 40 km/h is 11.1 m/s.
- In the second field enter time in seconds, for example 8. A minute is 60, not 1. Both fields need a number.
- Click Calculate. The calculator divides Δv by t. 27.8 m/s in 8 s gives about 3.47 m/s². In 10 s the same change is 2.78 m/s².
- Zero time will not run, because you divide by t. Typed 0 in Δv gives 0 m/s². Δv in this calculator is a positive change.
- You already have a and want distance? Open accelerated motion. Force is on F = m·a. Braking is on decelerated motion. Here it stays a.
Formula
a = Δv / t
Δv is the speed change in m/s, t in seconds. Result a in m/s².
a, Δv, and t on a 0 to 100 run
Mean acceleration here is speed change over time. From 0 to 27.8 m/s in 8 s is about 3.47 m/s², compact-car order.
- a
- Acceleration in m/s²: a = Δv/t. From 0 to 27.8 m/s in 10 s is 2.78 m/s². Distance at that a is on the neighbouring page.
- Δv
- Speed change in m/s, first field. One hundred in the field is 100 m/s, not 100 on the speedometer.
- t
- Time in seconds. From 0 to 13.9 m/s in 8 s is about 1.74 m/s². Zero seconds does not divide.
- v₀
- Start speed when a problem gives a final v instead of Δv. Δv = final minus v₀, then the same a.
Real-life examples
Example 2
Zero to 40 km/h (11.1 m/s) in 12 s: easy enough to stand through.
Example 3
From 105 km/h (29 m/s) to a full stop in 3.5 s on dry pavement.
Example 4
First 2 s of the race: from the blocks to 10 m/s.
Example 5
Speeds up to 2.5 m/s in 2 s: you feel it in your knees.
Example 6
A passenger jet reaches about 250 km/h (69.4 m/s) in a 35 s takeoff roll.
Example 7
Zero to 20 km/h (5.6 m/s) in about 5 s of pedaling.
Example 8
From 0 to 161 km/h (44.7 m/s) in roughly 90 s.
Example 9
Kingda Ka-style launch: 0 to 206 km/h (57.2 m/s) in 3.5 s.
Example 10
A subway consist: 0 to 60 km/h (16.7 m/s) in 15 s.
Example 11
A dropped rock gains 9.81 m/s every second. Verify it: Δv = 9.81 m/s over 1 s.
Frequently asked questions
How many m/s² from 0 to 100 km/h in 8 s?
100 km/h = 27.8 m/s. a = 27.8 / 8 ≈ 3.47 m/s². Type 27.8, not 100. In 10 s the same change is 2.78 m/s².
Which units do I type?
Δv in m/s, time in seconds. Result in m/s². A minute is 60 s. 50 km/h ≈ 13.9 m/s.
Can I type 100 as km/h?
The field wants m/s. 100 km/h is 27.8 m/s. 100 in the field is 100 m/s, not a speedo hundred.
What if t = 0?
The calculator rejects zero seconds. You divide by t. Typed 0 in Δv gives 0 m/s². Both fields need a number.
Where is distance at this a?
On the accelerated-motion page. Here you compute a, there s and final speed from constant a, v₀, and t.
Can Δv be negative?
In this calculator Δv is a positive change. Braking lives on the decelerated-motion page, not as a minus here.
Does a comma in 27.8 work?
Yes. 27,8 and 27.8 are the same speed change. The calculator does not require a period.
Where is F = m·a?
On the force page. Here you have a, there you multiply by mass. This calculator stops at m/s².
Is this instantaneous a or mean a?
Mean a over the t in the field. There is no chart of instantaneous a here. Those 8 s are the whole interval, not one tap of the pedal.
How much from 0 to 13.9 m/s in 8 s?
a ≈ 1.74 m/s². 13.9 m/s is about 50 km/h. From 0 to 11.1 m/s in 12 s is about 0.93 m/s².
Knowledge sources
The formula is the school one. Units follow SI; NIST SP 330 and BIPM define the measures, not your result.
Page updated in 2026.