Can a Penny Dropped from a Skyscraper Kill Someone? The Physics Answer
False. A penny dropped from a skyscraper cannot kill anyone. Due to its flat, tumbling shape, a penny reaches a terminal velocity of only 25–65 km/h — far too slow to be lethal. Physicists and the MythBusters have confirmed that while it would sting, a falling penny cannot penetrate skin, break bone, or cause a fatal injury.
"A Penny Dropped from a Skyscraper Can Kill Someone" is a myth. The scientific consensus is clear, the primary sources are documented above, and the exact origin of the false belief can be traced. Read on for the full evidence.
"A Penny Dropped from a Skyscraper Can Kill Someone"
False.
Drop a penny from the Empire State Building and it could split open someone's skull. The claim has been repeated so often that it has become a standard scary fact about physics. It is also entirely false. The penny dropped from a great height is a classic physics myth — one that sounds plausible because it correctly identifies that falling objects gain speed, but ignores the crucial role of air resistance in limiting that speed. A penny is not a bullet. It is a thin, flat, light disc that tumbles through the air and reaches a terminal velocity roughly equivalent to a slow-moving car — uncomfortable if struck, but nowhere near lethal.
Terminal Velocity and Why Pennies Don't Reach Dangerous Speeds
All falling objects in an atmosphere experience air resistance — a force opposing their motion that increases with velocity. As an object falls faster, air resistance increases until it equals the gravitational force pulling the object down. At this point, the net force is zero, and the object stops accelerating. This is terminal velocity. Terminal velocity depends on the object's mass, cross-sectional area, and aerodynamic shape. A penny is flat, light (2.5 grams for a U.S. cent), and tumbles end-over-end when falling, presenting a large and irregular cross-section to the air. Physicists at the University of Virginia and elsewhere have calculated the terminal velocity of a tumbling penny at approximately 25 to 65 kilometres per hour (varying with tumbling pattern). For context, 65 km/h is approximately the speed limit on a suburban street — uncomfortable to be struck at, but not inherently lethal, especially from a small, light object. A baseball-sized hailstone reaches a similar terminal velocity and causes property damage and painful bruising but is rarely lethal. A penny, significantly lighter than a hailstone, would sting sharply but is incapable of penetrating skin or fracturing bone.
The MythBusters Test and Expert Physics
The penny drop myth was tested experimentally by the MythBusters television programme in their third season, using a combination of wind tunnel tests and live firing from height. They launched pennies from a pneumatic cannon at various velocities, tested impact on ballistic gelatin and bare skin, and measured pain and penetration. At velocities significantly above terminal velocity, pennies caused discomfort and red marks but did not penetrate skin. At terminal velocity, the impact was described as equivalent to a very firm flick — noticeable, painful, but not dangerous. Similarly, physicist Louis Bloomfield at the University of Virginia has conducted classroom demonstrations of penny terminal velocity, using slow-motion video to verify tumbling behaviour and measuring impact force. His analysis concludes that a penny at terminal velocity hitting a person would be painful but would not cause serious injury. The aerodynamic behaviour of the penny is critical: because it tumbles and wobbles, it presents different cross-sections at different moments, dramatically increasing drag compared to a stabilised projectile. If a penny fell perfectly flat (broadside to the air), its drag would be even higher and its terminal velocity even lower.
What Would Actually Be Dangerous from Height
The penny myth often implicitly rests on a conflation: height is impressive, height equals danger, therefore anything dropped from great height is dangerous. This ignores that height only determines the maximum speed an object could achieve if it fell in a vacuum — not the speed it actually reaches in air. What determines impact danger is terminal velocity, which is determined by physics of the object, not the height from which it falls. Objects that are genuinely dangerous when dropped from height share certain characteristics: they are heavy relative to their cross-sectional area (high ballistic coefficient), and their shape produces low drag. A steel bolt, a ball bearing, a compact metal tool — these objects have much higher terminal velocities and could cause serious injury if dropped from a skyscraper. A penny, a sheet of paper, a feather — these have low ballistic coefficients, high drag, and low terminal velocities. The takeaway is not 'nothing dropped from height is dangerous' but specifically 'a penny is the wrong shape and too light to be dangerous.'
The Verdict
A penny dropped from a skyscraper cannot kill anyone. Its terminal velocity is approximately 25–65 km/h, which is sufficient to sting but not to penetrate skin, fracture bone, or cause fatal injury. This has been confirmed by physics calculations and experimental testing. Height is irrelevant once an object reaches terminal velocity — a penny falling from the Empire State Building (443 metres) reaches terminal velocity well before it lands and strikes at exactly the same speed it would from any other height above its terminal velocity ceiling. The myth conflates 'more height means more danger' with the physics of air resistance, which caps the speed of any falling object regardless of drop height.
Other Common 'Dropped from Height' Myths
The penny myth illustrates a broader category of physics misconceptions based on the 'height = danger' intuition. Similar myths include the claim that a golf ball dropped from a skyscraper could kill, or that a small stone dropped from a helicopter could be lethal. Golf balls (45 grams, spherical, relatively aerodynamic) do reach higher terminal velocities than pennies — approximately 120–145 km/h — and a strike from a golf ball at that speed could cause serious bruising or, in a worst-case scenario, injury to sensitive areas like the eye or temple. But even this is not automatically lethal. Hailstones reaching similar speeds cause injuries but very rarely deaths, and hailstones can be considerably larger than golf balls. What actually is dangerous is a compact, heavy, low-drag object — a metal nut, a bolt, a glass bottle — which can reach terminal velocities of 120–200 km/h and have sufficient mass to concentrate force. Construction sites require hard-hat protection not because coins are lethal but because actual tools and fasteners can reach genuinely dangerous speeds. The physics literacy gap the penny myth reveals is real: understanding that air resistance, not gravity, sets the ceiling on falling-object danger is a fundamental insight with practical safety implications.
Primary Sources
Frequently Asked Questions
Can a penny dropped from the Empire State Building kill someone?
No. A penny reaches a terminal velocity of only 25–65 km/h due to its flat, tumbling shape and light weight. At this speed, it can sting but cannot penetrate skin or cause fatal injury. This has been confirmed by physics calculations and experimental testing.
What is terminal velocity and why does it matter here?
Terminal velocity is the maximum speed a falling object reaches, when air resistance equals gravitational force. A penny's flat, tumbling profile creates high drag, limiting its terminal velocity to well below dangerous speeds — regardless of how high it is dropped from.
Has the penny drop myth been tested experimentally?
Yes — the MythBusters tested it by firing pennies at and above terminal velocity at ballistic gelatin and bare skin. Results: pennies at terminal velocity caused painful stinging but no penetration. Physicist Louis Bloomfield at UVA has also measured penny terminal velocity in demonstrations.
What would actually be dangerous if dropped from a skyscraper?
Objects with high mass relative to their cross-sectional area (high ballistic coefficient) and streamlined shape — metal bolts, ball bearings, compact tools. These can reach terminal velocities of 120–200 km/h with sufficient mass to concentrate force. Construction safety rules exist for exactly this reason.
Why does height not make the penny more dangerous?
Once a falling object reaches terminal velocity, additional height provides no extra speed. A penny reaches its terminal velocity of ~25–65 km/h well before reaching the ground from any skyscraper height. It strikes at the same speed from 400m as from 200m.
How fast does a penny actually fall?
A tumbling penny reaches terminal velocity of approximately 25–65 km/h. The range reflects variation in tumbling pattern. A penny falling perfectly flat would reach an even lower terminal velocity due to higher drag.
What about other coins — are bigger, heavier coins more dangerous?
Larger coins have more mass but also more surface area. Their ballistic coefficient is similar to a penny's, so their terminal velocities are in a similar range. No standard coin is dense or streamlined enough to reach lethal terminal velocities in open air.
How We Verified This Claim
SmartAss Facts evaluates every popular belief against a three-tier source hierarchy: primary sources (peer-reviewed research, government datasets, and court records), secondary sources (reputable journalism citing the primary), and tertiary sources (blogs and general reference sites). Only primary sources are cited. If a claim can only be traced to a blog or an unsourced assertion, it is not used.
For this myth — A Penny Dropped from a Skyscraper Can Kill Someone — we reviewed the cited primary sources above, cross-referenced against independent scientific literature, and confirmed the verdict with the consensus position of relevant professional bodies (including the sources listed). The claim was then fact-checked against the SmartAss Facts database of over 5,000 verified facts to identify related content.
If you believe our verdict is incorrect or you have a more recent primary source that changes the analysis, the science always wins — we revise pages when the evidence warrants it. Last reviewed: 2026-05-23.
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