Interactive Meteor Impact Calculator
Estimate impact energy, TNT equivalent, and potential crater size from a meteoroid entering Earth’s atmosphere. This tool is for educational use and provides order-of-magnitude estimates, not official hazard forecasts.
Note: Real impact outcomes depend on composition, fragmentation, entry heating, local geology, and atmospheric behavior.
What this meteor impact calculator does
This calculator models a simplified asteroid or meteoroid impact scenario. You enter the object size, density, speed, angle, and target surface. The tool then estimates:
- Impactor mass
- Kinetic energy at impact
- TNT equivalent (kilotons and megatons)
- Approximate crater diameter and depth
- A qualitative severity category
How the math works (in plain language)
1) Mass of the impactor
The impactor is modeled as a sphere. Mass is computed from the sphere’s volume and your chosen density:
mass = (4/3) × π × radius³ × density
2) Impact energy
Energy is estimated from classical kinetic energy:
energy = 0.5 × mass × velocity²
Because angle matters, the model uses the vertical component of impact speed as a first-order correction.
3) TNT equivalent and crater scaling
Energy is converted to TNT equivalent using standard conversion factors. Crater size is estimated with a simplified scaling law using diameter, speed, angle, and surface type. This gives a useful approximation, not a high-fidelity geological simulation.
How to interpret the results
Think in ranges, not exact numbers. For example:
- Very low yield: likely atmospheric breakup or bright fireball event.
- Kiloton range: local blast damage possible, especially if airburst occurs.
- Megaton range: potentially severe regional effects.
- Hundreds+ of megatons: large-scale devastation and possible wider environmental effects.
Example scenarios
Small stony meteoroid (5 m)
Often fragments in the atmosphere. Even when energy is significant, a ground crater may be small or absent because of breakup before impact.
Medium object (50 m)
Can produce a major airburst or crater depending on composition and entry angle. This is the size class often discussed in regional hazard studies.
Large asteroid (500 m+)
Extremely high energy release, major crater formation, and potentially widespread consequences well beyond the immediate blast zone.
Important limitations
- No full atmospheric-entry simulation (ablation and fragmentation are simplified).
- No precise seismic, tsunami, or ejecta-field model.
- No local terrain or city-level shielding calculations.
- No probabilistic uncertainty bands.
For mission planning or official risk assessment, use professional planetary defense models and peer-reviewed tools.
Quick terminology refresher
- Meteoroid: small rocky/metal object in space.
- Meteor: light streak when an object burns in the atmosphere.
- Meteorite: piece that survives to reach the ground.
- Asteroid: larger rocky body orbiting the Sun.
Bottom line
This meteor impact calculator is a practical way to build intuition about asteroid impact energy and crater formation. Use it to compare scenarios, learn the role of impact velocity and angle, and understand why even modest changes in size can dramatically change outcomes.