Aircraft Center Of Gravity Calculator

Calculate total aircraft weight, total moment, and loaded center of gravity using a professional, easy-to-audit loading worksheet. Enter your station weights and arms, then visualize your loaded point against a representative CG envelope chart.

Interactive CG and Weight & Balance Calculator

Use the fields below to enter weight at each station. The calculator multiplies each weight by its arm to determine moment, then divides total moment by total weight to calculate loaded center of gravity.

Expert Guide to Using an Aircraft Center of Gravity Calculator

An aircraft center of gravity calculator is one of the most practical tools in weight and balance planning. Every pilot learns the phrase weight and balance early in training, but the importance of center of gravity becomes even more obvious with experience. A load sheet that looks acceptable at first glance can still produce poor elevator authority, longer takeoff distance, reduced climb performance, increased stall speed, or degraded spin recovery if the center of gravity falls outside approved limits. That is why a calculator like the one above is useful: it converts loading data into a clear, auditable result showing total weight, total moment, and the exact loaded CG.

At its core, center of gravity is simply the balance point of the aircraft. When you load people, baggage, and fuel, you are not just adding weight. You are adding weight at a specific arm, or distance from the datum. Multiply each station weight by its arm and you get a moment. Add all moments together, then divide by total weight. The result is the loaded center of gravity in inches from the datum. The process is straightforward, but real-world loading changes quickly, especially when fuel burn or baggage loading shifts the overall balance.

Why center of gravity matters so much

The aircraft must be within both the approved weight limit and the approved CG envelope. Pilots sometimes focus heavily on gross weight, yet the center of gravity can be equally critical. A forward CG generally produces greater longitudinal stability, but it can also require higher tail-down force, increase induced drag, and make rotation and flare more difficult. An aft CG may reduce tail download and trim drag, but too much aft loading can make the aircraft less stable and harder to recover from stalls or spins. In some airplanes, aft loading can also reduce elevator effectiveness at critical moments.

That is why your pilot operating handbook, aircraft flight manual, or approved weight and balance records are the final authority. A calculator is a fast planning tool, but the approved aircraft data remains the legal and operational standard. For regulatory and training reference material, consult the Federal Aviation Administration, FAA handbooks, and university aviation programs such as Embry-Riddle Aeronautical University. You may also find useful technical references through FAA Airplane Flying Handbook resources.

How an aircraft CG calculator works

This calculator follows the same logic used in manual weight and balance worksheets:

1. Enter the aircraft empty weight and empty arm.
2. Enter the weight and arm for each occupied station.
3. Convert fuel quantity to fuel weight using a known fuel density.
4. Multiply each station weight by its arm to get moment.
5. Add all station weights to get total loaded weight.
6. Add all station moments to get total moment.
7. Divide total moment by total weight to determine loaded CG.
8. Compare the result to the approved forward and aft CG limits and to maximum gross weight.

The chart beside the calculator helps you visualize your loading point. In practical dispatch work, this is often the easiest way to see whether your airplane is both within gross weight and inside the CG envelope. Visual confirmation is especially useful when you are comparing several loading options, such as moving baggage, reducing fuel, or changing seating assignments.

Understanding the key inputs

• Empty weight: The baseline aircraft weight from official records, including installed equipment and unusable fuel, as defined by the applicable data for that aircraft.
• Arm: The horizontal distance from the reference datum to the station.
• Moment: Weight multiplied by arm. This is what determines the turning effect around the datum.
• Fuel density: Required if you enter fuel in gallons. For typical planning, avgas is commonly approximated at 6.0 lb/gal and Jet A around 6.7 lb/gal.
• CG envelope: The approved operating area that combines allowable weight and balance limits.

Fuel Type	Typical Planning Density	Use in Calculator	Operational Note
100LL Avgas	6.0 lb/gal	Multiply gallons by 6.0 to get fuel weight	Common for piston trainers and touring singles
Jet A	6.7 lb/gal	Multiply gallons by 6.7 to get fuel weight	Common for turboprops and many turbine aircraft
Mogas	About 6.3 lb/gal	Use only when approved for the aircraft and operation	Density can vary, so verify with actual approved data when needed

One of the biggest reasons calculations go wrong is a mismatch between arms used in the worksheet and arms approved in the actual aircraft records. Another frequent error is forgetting to convert fuel quantity into fuel weight before adding it to total weight. A third common issue is using rounded weights for passengers and bags without checking whether seasonal clothing, survival equipment, or mission gear significantly changes the real number.

Representative loading example

Imagine a typical four-seat training aircraft with an empty weight of 1,663 lb at an empty arm of 39.5 inches. Add a 170 lb pilot and a 150 lb front passenger at 37 inches, 20 lb of baggage at 95 inches, and 40 gallons of avgas at 48 inches. The fuel contributes 240 lb of weight because 40 x 6.0 = 240. The resulting total loaded weight is 2,243 lb. Total moment is the sum of each station moment. Dividing total moment by total weight gives a loaded center of gravity of about 42.15 inches. That result may fit comfortably in a representative trainer envelope, but the final determination must be checked against the specific aircraft documents.

Scenario	Total Weight	Loaded CG	Interpretation
Dual instruction, moderate fuel, light baggage	2,243 lb	42.15 in	Typically well inside many trainer envelopes, but verify POH
Add 200 lb rear passengers at 73 in	2,443 lb	44.67 in	CG moves aft noticeably while staying under many common gross limits
Add 120 lb baggage at 95 in with rear seats occupied	2,543 lb	46.66 in	Near or over common trainer gross limits and much closer to aft boundary

These figures are useful because they show how quickly the CG can move aft when rear seats and baggage are loaded together. Many pilots are surprised that a small amount of baggage placed at a long arm can have a large effect on total moment. This is exactly why a calculator is valuable. It turns what looks like a simple loading change into a measurable shift on the chart.

Forward CG versus aft CG behavior

A forward center of gravity generally increases static stability. The aircraft may feel more solid in pitch, but it may also require more back pressure during landing flare and more trim during climb. In some models, a forward CG can lengthen takeoff roll and reduce climb performance because the tail must produce greater downward force. Conversely, an aft CG often reduces trim drag and may slightly improve cruise efficiency, but it can also make the aircraft more sensitive in pitch. More importantly, excessive aft loading may significantly compromise stall and spin characteristics.

The practical lesson is simple: an aircraft within gross weight but outside the aft CG limit is not safely or legally loaded. An aircraft inside the CG envelope but over maximum gross weight is also unacceptable. Weight and balance is a two-part requirement. The calculator above displays both so you can make better loading decisions before engine start.

Best practices when using any center of gravity calculator

• Always begin with the latest official empty weight and balance record for that exact aircraft.
• Use station arms from the approved documentation, not generic internet values.
• Weigh baggage and mission gear when accuracy matters.
• Account for fuel burn if the CG shifts significantly over the flight.
• Check both departure and landing conditions when required by the aircraft or mission profile.
• For turbine or complex aircraft, follow company procedures and AFM data exactly.
• Retain a written or digital record of the calculations as part of preflight planning.

Important: This calculator is intended for planning and educational use. It is not a substitute for the approved aircraft weight and balance documentation, pilot operating handbook, aircraft flight manual, or operator procedures. If any number in your records differs from a prefilled value in the calculator, the aircraft records always win.

Common mistakes pilots make

Even careful pilots can make avoidable errors in weight and balance. A classic mistake is assuming full fuel when the actual dispatch fuel is lower, or the opposite: using a planned fuel value when the tanks were topped. Another is forgetting to include oil, survival gear, tie-down equipment, or removable seats in aircraft where those items materially affect useful load. Some pilots also misread moment tables in POHs that divide moment by 100 or 1,000 for convenience. If a handbook expresses moment in a reduced format, you must use the same format consistently throughout the calculation.

A second category of mistakes involves seat swaps and baggage relocation. If a rear passenger moves to the front or a heavy bag is relocated to an aft compartment, the weight might stay the same but the moment can change enough to matter. In small aircraft, these changes are often operationally significant. That is why good pilots recalculate after any meaningful loading change, not just before the first leg.

How to use the chart effectively

The chart produced by this page plots your calculated loading point against a representative rectangular envelope defined by your minimum chart weight, maximum gross weight, and forward and aft arm limits. This is a simplified visualization, not a replacement for type-specific envelope charts, many of which have sloped or stepped boundaries. Still, it provides an immediate answer to the practical question pilots ask most often: is my loaded point generally where I expect it to be?

If your point appears too far aft, practical solutions include reducing aft baggage, moving passengers forward when the aircraft allows it, or carrying less fuel only when performance, reserves, and regulations still permit. If the aircraft is overweight, reducing fuel, baggage, or passenger load may be required. The correct solution depends on the mission, weather, runway performance, reserve requirements, and operating rules.

Authoritative references and continuing education

For formal guidance on aircraft loading, flight planning, and handling characteristics, review FAA publications and certified training resources. Good starting points include the FAA website at faa.gov, the FAA Airplane Flying Handbook page at faa.gov regulatory handbooks, and university aviation educational materials at eaglepubs.erau.edu. These resources help pilots connect the numbers on a worksheet to real aerodynamic consequences in the airplane.

Final takeaway

An aircraft center of gravity calculator is valuable because it transforms loading assumptions into objective data. It helps you see how seat assignments, baggage placement, and fuel quantity affect total weight and balance. Used correctly, it improves safety margins, supports regulatory compliance, and reduces surprises in takeoff, climb, cruise, approach, and landing. Use the calculator above as a planning aid, but always validate the final answer against the approved records for your exact aircraft. In aviation, precision is professionalism, and weight and balance is one of the best places to prove it.

Planning tool only. Always verify all arms, station limits, and loading envelopes using the specific aircraft pilot operating handbook, aircraft flight manual, and current weight and balance documentation.