Crabwise

Crabwise, an E6B flight computer for student and private pilots

The six calculations you learn on paper, with type large enough to read at a glance, and it works offline.

Free to download

Crabwise Pro is an optional one-time purchase that adds aircraft profiles, a leg planner, weight and balance, and history export.

Crabwise home grid with six calculators: Wind and GS, Density Alt, True Airspeed, Fuel Time Dist, Crosswind, Weight and BalanceWind correction screen with a compass dial showing course, wind, and headingWeight and balance screen with a CG envelope graph showing the loaded point within limits

How it works

How it works

Wind and ground speed

Solve the wind triangle either direction: find your heading and ground speed, or work backward from heading, track and ground speed to find the wind.

Density altitude and true airspeed

See the classroom rule of thumb next to the exact ICAO Doc 7488 answer, plus true airspeed and Mach with the quick approximation and the exact compressible calculation.

Fuel, crosswind and conversions

Solve for any one of fuel, time or distance from the other two, find headwind and crosswind components for any runway and wind, and convert across seven unit families.

Crabwise Pro

A one-time purchase adds aircraft profiles, a leg planner with running totals, weight and balance checked live as you type, and history with export to text or CSV.

Who it is for

Student and private pilots who want the E6B's six calculations on their phone, for training and planning cross-checks.

FAQ

Frequently asked questions

What can Crabwise calculate?
Wind and ground speed, pressure and density altitude, true airspeed and Mach, fuel, time and distance, crosswind, and unit conversions across seven unit families.
Is it free?
Yes. All six calculators, every unit, and extra-large type are free forever, with no ads and no trial timer.
What does Crabwise Pro add?
Aircraft profiles, a leg planner, weight and balance checked live as you type, and history with export to text or CSV, for a one-time purchase.
Can I use it for primary navigation?
No. Crabwise is for training and planning cross-checks. Always verify against your aircraft flight manual and official sources.
Does it work offline?
Yes. Crabwise works offline, with no account, no ads and no tracking.

Get Crabwise for your next flight.

Free to download on the App Store and Google Play.