Acceleration converter

This converter anchors every unit to the meter per second squared (m/s²), the SI unit for the rate at which velocity changes. Everyday and industry units are just that same quantity rescaled: standard gravity (g) is fixed at exactly 9.80665 m/s² (the conventional average pull of Earth's gravity at sea level), foot per second squared uses the imperial foot (1 ft/s² = 0.3048 m/s²), and Gal (1 Gal = 0.01 m/s²) is a centimeter-based unit that geophysicists still use for gravity surveys, with its subunit milligal (1 mGal = 1e-05 m/s²) fine enough to register tiny variations caused by underground rock density changes.

To convert meter per second squared to standard gravity, multiply by g = m/s² × 0.1019716213, which is simply 1 ÷ 9.80665. Reverse the conversion by multiplying by 9.80665 instead. The same approach applies to any of the other units: divide the known unit's own factor into the target unit's factor, or equivalently multiply by the ratio of the two factors, to move between any pair on this page.

A car that accelerates from 0 to 60 mph in 6 seconds is speeding up at roughly 4.4704 m/s² on average, which converts to 4.4704 × 0.1019716213 ≈ 0.456 g — noticeably gentler than the 1 g you feel standing still under gravity. A rollercoaster drop pulling 2 g, on the other hand, works out to 2 × 9.80665 = 19.613 m/s², more than twice the acceleration of a hard sports-car launch. A third comparison: the imperial "standard gravity" value of 32.2 ft/s² that US textbooks often use converts to 32.2 × 0.3048 ≈ 9.815 m/s², close to but not perfectly matching the exact SI value of 9.80665 m/s², a small rounding difference worth knowing about when comparing US and metric textbook answers.

Engineers reach for different units depending on the field: automotive and aerospace testing reports braking and crash-test forces in g because it is intuitive relative to human tolerance limits, seismologists and structural engineers describe earthquake ground motion in both g and Gal (older USGS and seismic-hazard maps often use Gal and milligal), and vibration or shock testing of electronics frequently specifies tolerances in g for the same reason — it is immediately comparable to what a component would feel if dropped. Pilots and astronauts likewise train for sustained g-loads during high-performance maneuvers or launch, where the body's tolerance to acceleration, not the acceleration itself, becomes the limiting design factor.

A frequent point of confusion is mixing up g-force with the acceleration of gravity itself: 1 g is a fixed reference value (9.80665 m/s²) used to express any acceleration as a multiple of gravity, not a measurement that changes with location, even though actual gravitational acceleration varies slightly across the Earth's surface. It's also easy to confuse mile per second squared (a huge unit, since a mile is 1,609.344 m) with mile per hour per second (mph/s, a much smaller, more practical rate used for describing how quickly speed in mph builds up) — the two differ by a factor of 3,600.

It's also worth remembering that acceleration alone doesn't describe how smoothly a ride or a motion feels — that is the job of jerk, the rate of change of acceleration, which this page does not cover. Two vehicles can reach the same peak g-force but feel completely different if one applies it abruptly and the other ramps into it gradually, so acceleration figures are best read alongside the time profile they were measured over, not as a single number in isolation.