Crabwise: E6B Flight Computer

Wind, density altitude, true airspeed, weight and balance, fuel and crosswind: exact math and the classroom rule of thumb, side by side. No ads, no account, bought once.

Crabwise is an offline E6B flight computer built for student and private pilots: the six calculations you learn on paper, with type large enough to read at a glance.

WIND & GROUND SPEED Solve the wind triangle both directions: find your heading and ground speed, or work backward from heading, track, and ground speed to find the wind.

PRESSURE & DENSITY ALTITUDE See the classroom rule of thumb and the exact ICAO Doc 7488 answer side by side, so you know how much margin you actually have.

TRUE AIRSPEED & MACH The quick 2%-per-1000-ft approximation and the exact compressible calculation, together.

FUEL / TIME / DISTANCE Solve for any one of the three from the other two.

CROSSWIND Headwind and crosswind components for any runway and wind.

CONVERSIONS Seven unit families: distance, speed, altitude, temperature, pressure, weight, volume.

CRABWISE PRO, ONE-TIME PURCHASE ($9.99)

• Aircraft profiles: save cruise speed, fuel burn, usable fuel, empty weight and arm, and limits for every aircraft you fly.
• Leg planner: chain legs from true course to compass heading, with running totals for time and fuel.
• Weight & balance: plot your loading against your aircraft's envelope, checked live as you type.
• History & export: save any result and export it as text or CSV.

Free forever: all six calculators, every unit, every language, extra-large type. No ads, ever. No trial timer, no subscription.

For training and planning cross-checks. Always verify against your aircraft flight manual and official sources. Not for primary navigation.

No account. No ads. No tracking. Works offline.

Available in English, Spanish, and Polish.