Equal Earth — Interactive Map Projection Lab

DRAG THE WORLD

SOURCE · SPHERE DRAG

STEP 01 · PARAMETRIC LATITUDE

θ = asin(m · sin φ)

m = √3 / 2

STEP 02 · VERTICAL SHAPE

y = θ(A₁ + A₂θ² + A₃θ⁶ + A₄θ⁸)

STEP 03 · KEEP IT EQUAL-AREA

x = λ cos θ /
m(A₁ + 3A₂θ² + 7A₃θ⁶ + 9A₄θ⁸)

SHAPE COEFFICIENTS

Change the vertical shape. The x formula compensates automatically so the projection remains equal-area.

A₁ A₂ A₃ A₄

HORIZONTAL POSITION

x = Rλ

Longitude maps directly to horizontal position.

VERTICAL POSITION

y = R ln(tan(π/4 + φ/2))

Latitude grows logarithmically towards the poles.

PRESERVES Local angles

Small shapes remain locally conformal. Tissot indicatrices stay circular.

DISTORTS Area

Scale increases dramatically as latitude approaches either pole.

VIEWPORT CUT-OFF ±75°

Mercator itself extends indefinitely towards the poles. This view is cropped at ±75° to fit the map frame.