Earth Science
Earth Curvature Calculator
How much the Earth curves away over a distance, and how much of a distant object is hidden.
drop ≈ d² / 2R
Also called curvature drop · how much does earth curve
Science · 7 calculators
Earth Science Calculators
Earth curvature, distance to the horizon, altitude from pressure, slope grade and angle, geologic time and map scales.
Earth Science
Horizon Distance Calculator
How far you can see to the horizon from any height, with and without atmospheric refraction.
d ≈ 3.86 × √h (km, h in metres, with refr…
Also called how far is the horizon · line of sight distance
Earth Science
Elevation Difference Calculator
Elevation gain, grade and air pressure change between two points, with the walking effort estimate.
grade = rise ÷ run × 100
Also called elevation gain · altitude difference
Earth Science
Slope Percentage Calculator
Convert between slope percentage, degrees, ratio and rise over run for land, roads and ramps.
slope % = rise ÷ run × 100
Also called grade to degrees · slope angle calculator
Earth Science
Density Calculator
Density, mass or volume (ρ = m/V) — with the result also in g/cm³ and lb/ft³.
ρ = m / V
Also called density formula · mass volume density
Earth Science
Geologic Time Calculator
Place a date in the geologic time scale, and scale Earth’s history onto a single calendar year.
Earth is 4,600 million years old — scale …
Also called geological time scale · millions of years ago
Earth Science
Map Scale Calculator
Convert between map distance and real distance at any scale, and find the scale from a known pair.
real distance = map distance × scale deno…
Also called scale conversion · map distance calculator
Key earth science formulas
| Earth Curvature | drop ≈ d² / 2R · horizon = √(2Rh) |
|---|---|
| Horizon Distance | d ≈ 3.86 × √h (km, h in metres, with refraction) |
| Elevation Difference | grade = rise ÷ run × 100 |
| Slope Percentage | slope % = rise ÷ run × 100 · angle = arctan(rise/run) |
| Density | ρ = m / V |
| Geologic Time | Earth is 4,600 million years old — scale any date against that |
| Map Scale | real distance = map distance × scale denominator |