Acceleration Calculator
Calculate acceleration from velocity change, distance, or gravitational force
Calculate acceleration from velocity change: a = Δv / t
What Is Acceleration?
Acceleration is the rate at which velocity changes over time. It is measured in meters per second squared (m/s²): an acceleration of 3 m/s² means an object gains 3 m/s of speed every second. Acceleration can be positive (speeding up), negative (slowing down, often called deceleration), or a change in direction at constant speed, as in circular motion.
The Formulas This Calculator Uses
- From velocity change: a = (v − v₀) / t. Enter initial velocity, final velocity, and time, and the calculator returns the average acceleration over that interval.
- From distance: a = 2(d − v₀t) / t². This rearranges the kinematic equation d = v₀t + ½at², useful when you know how far something traveled in a given time but not its final speed.
- Gravity mode: uses the local gravitational acceleration of a chosen planet to compute weight (W = mg) and free-fall time and impact velocity from a drop height (t = √(2h/g), v = gt).
Worked Example
A car accelerates from rest (v₀ = 0 m/s) to highway speed, 27.8 m/s (100 km/h), in 8 seconds. Its average acceleration is a = (27.8 − 0) / 8 = 3.475 m/s². For comparison, that is about 0.35 g, where 1 g = 9.81 m/s² is the acceleration due to gravity at Earth's surface.
Gravitational Acceleration Across the Solar System
Surface gravity varies dramatically between bodies. Approximate values: Mercury 3.7 m/s², Venus 8.87 m/s², Earth 9.81 m/s², the Moon 1.62 m/s², Mars 3.71 m/s², Jupiter 24.79 m/s², Saturn 10.44 m/s², Uranus 8.87 m/s², and Neptune 11.15 m/s². A 70 kg person weighs 686.7 N on Earth but only 113.4 N on the Moon — the same mass, one-sixth the weight.
Common Uses
- Physics homework: solve kinematics problems and check answers step by step with the formula shown.
- Automotive: convert 0–100 km/h or 0–60 mph times into m/s² or g-forces.
- Engineering and safety: estimate deceleration during braking or impact, which drives seat belt and crumple-zone design.
- Astronomy education: compare weight and fall times on different planets.
Frequently Asked Questions
How do I calculate acceleration from velocity and time?+
Use the formula a = (final velocity − initial velocity) ÷ time. For example, going from 10 m/s to 30 m/s in 5 seconds gives a = (30 − 10) / 5 = 4 m/s². Enter the two velocities and the time in the Basic tab and the calculator does this instantly, showing the formula used.
What is the difference between acceleration and deceleration?+
Deceleration is simply acceleration with a negative sign — the object is slowing down. If a car goes from 25 m/s to 5 m/s in 4 seconds, its acceleration is (5 − 25) / 4 = −5 m/s². The calculator handles negative results automatically, so you can compute braking rates the same way as speeding up.
How do I find acceleration when I only know distance and time?+
Use the Distance tab, which applies the kinematic equation d = v₀t + ½at², rearranged to a = 2(d − v₀t) / t². For an object starting from rest that covers 100 m in 10 s, acceleration is 2 × 100 / 100 = 2 m/s². You can also enter a non-zero starting velocity.
What is 1 g of acceleration?+
One g equals 9.81 m/s², the standard acceleration due to gravity at Earth's surface. It is a convenient benchmark: a sports car might pull about 0.9 g while braking, and fighter pilots experience up to 9 g in tight turns. The Gravity tab lets you compare g values on other planets, from 1.62 m/s² on the Moon to 24.79 m/s² on Jupiter.
Is this acceleration calculator free to use?+
Yes. It is completely free, requires no account or sign-up, and runs entirely in your browser — no data is sent to a server. It works on phones, tablets, and desktops, so you can use it in class, in the lab, or anywhere else.
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