Aviation calculators.
Your online E6B.
Fuel, wind, altitude, and the numbers behind your next flight. Choose a tool, work through the inputs, and understand the result.
What do you want to calculate?
Fuel Burn & Trip Fuel
Calculate enroute fuel, your chosen reserve, and extra allowances.
Density Altitude
See how pressure altitude and temperature change air density.
Wind Correction & Groundspeed
Solve the wind triangle for heading, drift correction, and groundspeed.
Runway Crosswind
Resolve steady and gust winds into crosswind and headwind or tailwind.
Time, Speed & Distance
Choose the unknown and calculate it from the other two values.
Fuel Endurance & Range
Find planning time and range with your selected reserve set aside.
Pressure Altitude
Convert field elevation and altimeter setting to approximate pressure altitude.
True Airspeed & Mach
Estimate TAS from calibrated airspeed, pressure altitude, and static temperature.
Find Winds Aloft
Work backward from heading, track, TAS, and groundspeed.
True, Magnetic & Compass
Apply signed variation and deviation without losing the direction.
Climb Gradient & Rate
Convert a required gradient into a vertical-speed target.
Top of Descent
Calculate descent time and distance with an optional level-off buffer.
Off-Course Correction
Estimate track error and an intercept toward your destination.
Still-Air Glide Range
Turn available height and a glide ratio into a theoretical distance.
Fuel Volume & Weight
Convert fuel volume to weight using an explicit density.
Aviation Unit Converter
Convert distance, speed, volume, mass, pressure, temperature, and time.
Flight Time Converter
Switch between hours/minutes/seconds and decimal flight hours.
Convective Cloud Base
Estimate a convective cloud base from surface temperature and dew point.
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Fuel Burn & Trip Fuel
Calculate enroute fuel, your chosen reserve, and extra allowances.
Enter your numbers
Example values are shown. Replace them with your own planning figures.
Your result
Check the inputs, then select Calculate.
Calculated from the values you enter.
No live weather or aircraft data is fetched.
How this calculation works
Trip fuel = fuel flow x enroute minutes / 60. Add reserve fuel (at the entered flow) and your separate allowances. For example, 9 gal/hr for 90 minutes uses 13.5 gallons before reserve and extras.
Assumptions & limits
Sample values are not aircraft performance data. Reserve requirements depend on the operation; this tool does not select a legal reserve or include an alternate automatically. Use phase-specific POH fuel figures when they differ.
Density Altitude
See how pressure altitude and temperature change air density.
Enter your numbers
Example values are shown. Replace them with your own planning figures.
Your result
Check the inputs, then select Calculate.
Calculated from the values you enter.
No live weather or aircraft data is fetched.
How this calculation works
The dry-air model finds pressure from pressure altitude in the standard troposphere, calculates density from pressure and absolute temperature, then finds the standard-atmosphere altitude with that density. ISA temperature is 15 C minus 1.9812 C per 1,000 ft.
Assumptions & limits
Use pressure altitude, not airport elevation. This estimate excludes humidity and does not predict takeoff distance or climb capability. Compare with official weather and your aircraft performance charts. Inputs are limited to -2,000 through 20,000 ft pressure altitude.
Wind Correction & Groundspeed
Solve the wind triangle for heading, drift correction, and groundspeed.
Enter your numbers
Example values are shown. Replace them with your own planning figures.
Your result
Check the inputs, then select Calculate.
Calculated from the values you enter.
No live weather or aircraft data is fetched.
How this calculation works
Wind correction is asin(crosswind / TAS). Groundspeed is TAS x cos(correction) minus the headwind component. Add the signed correction to your true course to obtain true heading.
Assumptions & limits
All directions here are TRUE and winds are FROM the stated direction. An impossible crosswind or zero/negative forward groundspeed produces a warning, not a usable heading. Forecast wind can differ from actual conditions.
Runway Crosswind
Resolve steady and gust winds into crosswind and headwind or tailwind.
Enter your numbers
Example values are shown. Replace them with your own planning figures.
Your result
Check the inputs, then select Calculate.
Calculated from the values you enter.
No live weather or aircraft data is fetched.
How this calculation works
Crosswind = wind speed x sin(wind direction minus runway heading). Headwind = wind speed x cos(the same angle); a negative headwind is a tailwind. The gust calculation assumes the same direction.
Assumptions & limits
Use the SAME true or magnetic reference for both headings. Use actual runway heading, not just the rounded runway number. METAR winds are true; local tower/ATIS reports are generally magnetic. Results do not determine whether a landing is safe or within aircraft limits.
Time, Speed & Distance
Choose the unknown and calculate it from the other two values.
Enter your numbers
Example values are shown. Replace them with your own planning figures.
Your result
Check the inputs, then select Calculate.
Calculated from the values you enter.
No live weather or aircraft data is fetched.
How this calculation works
Distance = groundspeed x hours. Time = distance / groundspeed. Groundspeed = distance / hours. At 120 kt, 150 NM takes 75 minutes.
Assumptions & limits
Use groundspeed, not indicated or true airspeed. This assumes a constant speed and does not add taxi, climb, holds, or delays.
Fuel Endurance & Range
Find planning time and range with your selected reserve set aside.
Enter your numbers
Example values are shown. Replace them with your own planning figures.
Your result
Check the inputs, then select Calculate.
Calculated from the values you enter.
No live weather or aircraft data is fetched.
How this calculation works
Available trip fuel = usable fuel minus extra allowances minus reserve fuel. Planning endurance = available trip fuel / fuel flow; planning range = endurance x groundspeed.
Assumptions & limits
Do not plan to run a tank dry. Only usable fuel belongs in the first field. Reserve adequacy, alternates, variable fuel flow and changing wind must be checked separately. A sample 45-minute reserve is not a legal determination.
Pressure Altitude
Convert field elevation and altimeter setting to approximate pressure altitude.
Enter your numbers
Example values are shown. Replace them with your own planning figures.
Your result
Check the inputs, then select Calculate.
Calculated from the values you enter.
No live weather or aircraft data is fetched.
How this calculation works
Pressure altitude approximately equals field elevation + (29.92 minus altimeter setting) x 1,000. At 1,000 ft and 29.42 inHg, the result is approximately 1,500 ft.
Assumptions & limits
This is the familiar linear E6B training approximation. Pressure altitude is not height above terrain. Do not change an operating altimeter just to experiment with this formula in flight.
True Airspeed & Mach
Estimate TAS from calibrated airspeed, pressure altitude, and static temperature.
Enter your numbers
Example values are shown. Replace them with your own planning figures.
Your result
Check the inputs, then select Calculate.
Calculated from the values you enter.
No live weather or aircraft data is fetched.
How this calculation works
Calibrated airspeed determines impact pressure at standard sea-level conditions. Using static pressure at the entered pressure altitude, the subsonic pressure relation gives Mach. TAS = Mach x the local speed of sound.
Assumptions & limits
Use CAS after instrument/position corrections, not uncorrected IAS. Use static OAT, not an uncorrected ram-rise/TAT indication. Dry air, standard pressure-altitude relationship, and Mach below 0.8 only; no aircraft-specific probe correction is included.
Find Winds Aloft
Work backward from heading, track, TAS, and groundspeed.
Enter your numbers
Example values are shown. Replace them with your own planning figures.
Your result
Check the inputs, then select Calculate.
Calculated from the values you enter.
No live weather or aircraft data is fetched.
How this calculation works
The wind vector is the ground-velocity vector minus the aircraft's air-velocity vector. Reverse the resulting direction to report the direction the wind comes FROM.
Assumptions & limits
Heading and track must use the same TRUE reference and describe the same steady flight segment. GPS track alone is not heading. Instrument errors, turns, and changing speed can make the inferred wind unreliable.
True, Magnetic & Compass
Apply signed variation and deviation without losing the direction.
Enter your numbers
Example values are shown. Replace them with your own planning figures.
Your result
Check the inputs, then select Calculate.
Calculated from the values you enter.
No live weather or aircraft data is fetched.
How this calculation works
Moving from true to magnetic, subtract east variation or add west variation. Moving from magnetic to compass, subtract east deviation or add west deviation. Results wrap to 000 through 359 degrees.
Assumptions & limits
Use current chart variation. A real compass correction card may directly say 'for / steer'; follow that card instead of interpreting its listed headings as signed deviation. Deviation is heading-dependent.
Climb Gradient & Rate
Convert a required gradient into a vertical-speed target.
Enter your numbers
Example values are shown. Replace them with your own planning figures.
Your result
Check the inputs, then select Calculate.
Calculated from the values you enter.
No live weather or aircraft data is fetched.
How this calculation works
Required climb rate (ft/min) = gradient (ft/NM) x groundspeed / 60. A 200 ft/NM gradient at 90 kt needs 300 ft/min. Percent gradient = feet per NM / 6,076.11549 x 100.
Assumptions & limits
This calculates the rate required, not the rate your aircraft can achieve. Check the published procedure, aircraft POH, terrain, temperature, weight, wind, and any engine-out requirements separately.
Top of Descent
Calculate descent time and distance with an optional level-off buffer.
Enter your numbers
Example values are shown. Replace them with your own planning figures.
Your result
Check the inputs, then select Calculate.
Calculated from the values you enter.
No live weather or aircraft data is fetched.
How this calculation works
Time to descend = altitude to lose / descent rate. Descent distance = time x groundspeed / 60. Add your chosen buffer to find a planning start distance.
Assumptions & limits
Uses constant groundspeed and rate. This is not a VNAV clearance, approach path, terrain-clearance calculation, or power-setting recommendation. Allow for ATC, airspace, speed changes, and a stabilized arrival.
Off-Course Correction
Estimate track error and an intercept toward your destination.
Enter your numbers
Example values are shown. Replace them with your own planning figures.
Your result
Check the inputs, then select Calculate.
Calculated from the values you enter.
No live weather or aircraft data is fetched.
How this calculation works
Track error = atan(lateral error / along-course distance flown). Closing angle = atan(lateral error / along-course distance remaining). Their sum estimates a heading correction toward course under unchanged conditions.
Assumptions & limits
This geometric training estimate assumes steady drift and small errors, and is not an obstacle- or airspace-clearance guarantee. Confirm position and terrain before making a course change; it does not replace current navigation guidance.
Still-Air Glide Range
Turn available height and a glide ratio into a theoretical distance.
Enter your numbers
Example values are shown. Replace them with your own planning figures.
Your result
Check the inputs, then select Calculate.
Calculated from the values you enter.
No live weather or aircraft data is fetched.
How this calculation works
Theoretical horizontal distance = height x glide ratio. Divide feet by 6,076.11549 for nautical miles. At 3,000 ft and 9:1, still-air distance is about 4.4 NM.
Assumptions & limits
Not a reachable-landing-site prediction. No allowance for wind, turns, reaction time, terrain, configuration, propeller drag or a landing pattern. Use aircraft-specific glide data and maintain a substantial margin.
Fuel Volume & Weight
Convert fuel volume to weight using an explicit density.
Enter your numbers
Example values are shown. Replace them with your own planning figures.
Your result
Check the inputs, then select Calculate.
Calculated from the values you enter.
No live weather or aircraft data is fetched.
How this calculation works
Fuel weight = volume in US gallons x density in pounds per US gallon. Divide pounds by 2.20462262185 to obtain kilograms. Forty US gallons at 6.0 lb/gal weighs 240 lb.
Assumptions & limits
Fuel density changes with grade and temperature. Use the correct aircraft or supplier data, especially for weight and balance. This is not a CG or loading-envelope check. US and Imperial gallons are different.
Aviation Unit Converter
Convert distance, speed, volume, mass, pressure, temperature, and time.
Enter your numbers
Example values are shown. Replace them with your own planning figures.
Your result
Check the inputs, then select Calculate.
Calculated from the values you enter.
No live weather or aircraft data is fetched.
How this calculation works
Conversions use defined unit factors, including 1 NM = 1,852 m, 1 ft = 0.3048 m, 1 US gallon = 3.785411784 L, and 1 Imperial gallon = 4.54609 L. Temperature conversions include their scale offsets.
Assumptions & limits
A volume conversion does not convert fuel to weight. Use the separate fuel-weight tool for that. Negative inputs are allowed only for temperature, and temperatures below absolute zero are rejected.
Flight Time Converter
Switch between hours/minutes/seconds and decimal flight hours.
Enter your numbers
Example values are shown. Replace them with your own planning figures.
Your result
Check the inputs, then select Calculate.
Calculated from the values you enter.
No live weather or aircraft data is fetched.
How this calculation works
Decimal hours = whole hours + minutes / 60 + seconds / 3,600. A duration of 1 hour 30 minutes is 1.5 hours, not 1.30. Clock results round to the nearest second.
Assumptions & limits
This converts a duration, not a local time zone or date. Apply your operator's actual logging or billing policy; the tool does not decide what time is loggable.
Convective Cloud Base
Estimate a convective cloud base from surface temperature and dew point.
Enter your numbers
Example values are shown. Replace them with your own planning figures.
Your result
Check the inputs, then select Calculate.
Calculated from the values you enter.
No live weather or aircraft data is fetched.
How this calculation works
The rough convective estimate is (temperature minus dew point in C) x 400 feet above the observing surface. Add observation-site elevation for an approximate MSL value.
Assumptions & limits
This does not establish an actual ceiling or predict fog, frontal, layered, or terrain-driven clouds. Use current METARs, forecasts and observations for weather decisions and cloud-clearance requirements.
A flight computer.
Not a substitute for judgment.
These online aviation calculators bring core E6B-style calculations into one workspace: fuel burn, time and distance, wind correction, pressure and density altitude, true airspeed, and unit conversions. Extra planning tools help you explore descent profiles, climb gradients, and still-air glide distance.
Use them to work through a training problem, compare assumptions, or cross-check a number. Every tool states its units and limitations. A result is only as useful as the inputs behind it: a fuel-flow example is not a Cherokee performance chart, and a computed glide distance is not a promise that a landing site is reachable.
For aircraft-specific planning, begin with your approved POH/AFM, current observations and forecasts, and the actual route and loading. We intentionally do not provide generic takeoff-distance, landing-distance, weight-and-balance envelope, or flight-approval decisions.
Put the numbers into practice at DuBois Aviation →Using the aviation tools
Which tool should I use for fuel planning?
Use Fuel Burn & Trip Fuel when you know fuel flow and flight duration. Use Fuel Endurance & Range when you know usable fuel on board and want to see the time available after your reserve and extra allowances. Neither chooses the reserve required for your flight.
Why do density altitude calculators give slightly different answers?
Some use a temperature rule of thumb; others model air density and may include humidity. This page uses a dry-air standard-atmosphere model with pressure altitude and static temperature. The separate pressure-altitude calculator is a linear approximation. Small differences are expected; aircraft performance planning still requires the proper charts and current data.
Should I enter true or magnetic wind direction?
The wind-triangle and inferred-wind tools use true directions. The runway crosswind tool requires runway and wind directions in the same reference. Do not mix a true METAR wind with a magnetic runway heading without accounting for variation.
Can I use the calculators on my phone or share one tool?
Yes. Select an icon to open its calculator without leaving this page. Use Copy tool link to share that calculator, or All calculators to choose another. Links identify the tool but do not include your entered numbers. No login is required.
Are my calculation inputs sent to DuBois Aviation?
The calculations run in your browser; this tool does not submit or store your input values. The site's existing analytics may record which tool was opened or used, without those values. This page does not enroll you or submit a training inquiry.
Methods & reference material
Built by DuBois Aviation for pilot education. Reference material explains the underlying concepts; the sources below do not certify or endorse this website's calculators.
- FAA Pilot's Handbook of Aeronautical Knowledge: navigation, performance, flight instruments, and planning fundamentals.
- ASA E6-B Circular Flight Computer instructions: traditional flight-computer methods and unit conventions.
- Density-altitude derivation from the U.S. Standard Atmosphere: dry-air model and assumptions.
- National Weather Service density-altitude calculator: an independent weather reference that can also account for dew point; its inputs differ from this tool.
- NASA isentropic flow equations: subsonic pressure/Mach and speed-of-sound relationships.
- FAA AC 135-45: limitations and temperature/dew-point methods for estimating cloud height.
Calculator release 1.0 · September 2026 · Report a problem or ask an instructor