Free Aircraft Weight and Balance Calculator

Ensure your flight is safe and legal with our comprehensive weight and balance tool.

Aircraft Weight & Balance Calculator

Enter the details for your aircraft's current configuration to determine its Center of Gravity (CG) and total weight.

Weight & Balance Load Sheet

Item	Weight (lbs)	Arm (in)	Moment (lb-in)
Empty Weight	0	0	0
Forward Seat	0	0	0
Aft Seat	0	0	0
Baggage 1	0	0	0
Baggage 2	0	0	0
Fuel	0	0	0
Total Operating Weight	0		0

What is Aircraft Weight and Balance?

Aircraft weight and balance refers to the crucial process of determining and managing the total weight of an aircraft and the location of its center of gravity (CG) relative to its structural and aerodynamic limits. Every aircraft has a specific CG range within which it must be operated to maintain stability, control, and structural integrity. Operating an aircraft outside these limits can lead to serious control issues, reduced performance, and potentially a loss of control in flight. Understanding and performing accurate weight and balance calculations for your aircraft is not just a regulatory requirement; it's a fundamental aspect of flight safety. Our free aircraft weight and balance calculator is designed to simplify this complex task, offering pilots and aviation enthusiasts a quick and reliable tool to ensure their aircraft is properly loaded for every mission.

Who Should Use a Free Aircraft Weight and Balance Calculator?

This tool is essential for several groups within the aviation community:

• Private Pilots: For pre-flight planning of personal flights, ensuring compliance with personal aircraft limitations.
• Commercial Pilots: As a quick check or supplementary tool to their more detailed operational calculations, especially for charter or non-scheduled flights.
• Flight Instructors and Students: An invaluable resource for learning and reinforcing the principles of weight and balance in a practical, interactive way.
• Aircraft Owners and Operators: To manage their aircraft's weight and CG envelope effectively over time, especially after modifications or changes in typical loading.
• Aviation Enthusiasts: For understanding the complexities of aircraft operation and the critical role of weight and balance.

Common Misconceptions About Weight and Balance

Several common misconceptions exist regarding aircraft weight and balance:

• "It's just about not exceeding the maximum takeoff weight." While max weight is critical, the CG location is equally, if not more, important. An aircraft can be within its weight limit but still unsafe if the CG is too far forward or aft.
• "Modern aircraft have automatic systems, so manual calculation is unnecessary." While some aircraft have sophisticated systems, understanding the underlying principles and being able to perform manual checks is a vital pilot skill, especially in case of system malfunctions or for older aircraft.
• "Weight and balance only matters for small planes." This is untrue. All aircraft, from small piston singles to large commercial airliners, have strict weight and balance limitations that must be adhered to. The complexity and scale differ, but the principle remains the same.
• "Adding weight always moves the CG aft." This depends on where the weight is added relative to the datum. Adding weight forward of the CG will move it forward, while adding it aft will move it aft.

This comprehensive approach to the free aircraft weight and balance calculator aims to demystify these concepts.

Aircraft Weight and Balance Formula and Mathematical Explanation

The fundamental principle of aircraft weight and balance revolves around the concept of "moments." A moment is the product of a weight and its horizontal distance from a fixed reference point called the datum. The CG is then determined by the total moment divided by the total weight.

Step-by-Step Derivation

1. Establish the Datum: This is a reference line or point, usually on the aircraft's structure, from which all horizontal distances (arms) are measured. It's often located at the nose or firewall.
2. Determine the Arm for Each Item: Measure the horizontal distance from the datum to the center of gravity of each item (empty weight, occupants, baggage, fuel, etc.). This distance is the "arm."
3. Calculate the Moment for Each Item: Multiply the weight of each item by its respective arm. This gives you the moment for that item.
   Moment = Weight × Arm
4. Sum All Weights: Add up the weights of all items, including the empty weight of the aircraft, occupants, baggage, fuel, and any other payload. This gives the Total Weight.
   Total Weight = Σ Weights
5. Sum All Moments: Add up the moments calculated for each individual item. This gives the Total Moment.
   Total Moment = Σ (Weight × Arm)
6. Calculate the Center of Gravity (CG): Divide the Total Moment by the Total Weight. The result is the CG location.
   CG = Total Moment / Total Weight

Variable Explanations

Understanding the variables is key to using the free aircraft weight and balance calculator effectively:

• Weight: The mass of an item or the entire aircraft, typically measured in pounds (lbs) or kilograms (kg).
• Arm: The horizontal distance from the datum to the center of gravity of an item or the entire aircraft, typically measured in inches (in) or centimeters (cm). This can also be expressed as a percentage of the Mean Aerodynamic Chord (MAC) for many aircraft.
• Moment: The product of weight and its arm, representing the leverage effect of that weight. Usually measured in pound-inches (lb-in) or kilogram-centimeters (kg-cm).
• Datum: An imaginary vertical plane or line from which all horizontal distances are measured for weight and balance calculations.
• Empty Weight: The weight of the aircraft as manufactured, including fixed equipment, unused operating items (like unusable fuel), and fixed ballast.
• Empty Weight CG: The CG of the aircraft at its empty weight.
• Operating Weight: The total weight of the aircraft when loaded with crew, passengers, baggage, and usable fuel.
• Operating CG: The CG of the aircraft at its operating weight.
• CG Limits: The forward and aft CG positions within which the aircraft must be operated for safe flight.

Variables Table

Weight & Balance Variables

Variable	Meaning	Unit	Typical Range / Notes
Empty Weight	Weight of the aircraft without any payload.	lbs (or kg)	Varies greatly by aircraft type (e.g., 1000 – 50000+ lbs)
Empty Weight CG	Center of Gravity location of the empty aircraft.	inches from datum / % MAC	Specific to each aircraft; must be obtained from POH.
Occupant Weight	Weight of pilots and passengers.	lbs (or kg)	Average person ~170-200 lbs; check airline/operator standards.
Occupant Arm	Distance of occupants from datum.	inches from datum / % MAC	Seat-specific; found in aircraft POH.
Baggage Weight	Weight of cargo or luggage.	lbs (or kg)	Limited by compartment capacity and aircraft max weight.
Baggage Arm	Distance of baggage compartment from datum.	inches from datum / % MAC	Compartment-specific; found in aircraft POH.
Usable Fuel Weight	Weight of fuel available for use.	lbs (or kg)	Calculated from volume (gallons/liters) and fuel density.
Fuel Arm	Distance of fuel tanks from datum.	inches from datum / % MAC	Tank-specific; found in aircraft POH.
Moment	Weight multiplied by its arm.	lb-in (or kg-cm)	Can be large positive or negative values.
Total Weight	Sum of all weights aboard the aircraft.	lbs (or kg)	Must be less than or equal to Max Takeoff Weight.
Total Moment	Sum of all moments aboard the aircraft.	lb-in (or kg-cm)	Result of summing all individual moments.
CG	Center of Gravity location.	inches from datum / % MAC	Must fall within the aircraft's CG limits for safe flight.

Utilizing this information within our free aircraft weight and balance calculator ensures that these critical values are computed accurately.

Practical Examples (Real-World Use Cases)

Example 1: A Weekend Trip in a Cessna 172

A pilot is planning a weekend trip in a Cessna 172. They need to calculate the weight and balance for their flight.

Aircraft Details (from POH):

• Empty Weight: 1,550 lbs
• Empty Weight CG: 70.5 inches from datum
• Forward Seat Arm: 37 inches from datum
• Aft Seat Arm: 57 inches from datum
• Baggage Compartment 1 Arm: 86 inches from datum
• Usable Fuel Capacity: 42 gallons (approx. 252 lbs)
• Fuel Tank Arm: 40 inches from datum
• CG Limits: 63.1 to 99.9 inches from datum
• Max Takeoff Weight: 2,550 lbs

Loading Scenario:

• Pilot: 180 lbs
• Passenger: 160 lbs
• Baggage: 70 lbs
• Usable Fuel: 30 gallons (approx. 180 lbs)

Calculation Using the Free Aircraft Weight and Balance Calculator:

Inputs:

• Empty Weight: 1550 lbs
• Empty Weight CG: 70.5 in
• Forward Seat Weight: 180 lbs
• Forward Seat Arm: 37 in
• Aft Seat Weight: 160 lbs
• Aft Seat Arm: 57 in
• Baggage 1 Weight: 70 lbs
• Baggage 1 Arm: 86 in
• Fuel Weight: 180 lbs
• Fuel Arm: 40 in

Outputs:

• Total Weight: 1550 + 180 + 160 + 70 + 180 = 2140 lbs
• Total Moment: (1550 * 70.5) + (180 * 37) + (160 * 57) + (70 * 86) + (180 * 40) = 109275 + 6660 + 9120 + 6020 + 7200 = 138275 lb-in
• Current CG: 138275 lb-in / 2140 lbs = 64.61 inches from datum

Interpretation: The total weight (2140 lbs) is below the max takeoff weight (2550 lbs). The calculated CG (64.61 inches) is within the allowable limits (63.1 – 99.9 inches). This loading is safe and legal.

Example 2: Maximum Load in a Piper PA-28

A pilot is flying a Piper PA-28 and wants to load it to its maximum takeoff weight for a longer flight.

Aircraft Details (from POH):

• Empty Weight: 1,300 lbs
• Empty Weight CG: 7.5 inches aft of datum (datum is at the firewall)
• Forward Seat Arm: 32 inches from datum
• Aft Seat Arm: 54 inches from datum
• Baggage Compartment Arm: 81 inches from datum
• Usable Fuel Capacity: 48 gallons (approx. 288 lbs)
• Fuel Tank Arm: 38 inches from datum
• CG Limits: 6.0 to 10.5 inches aft of datum
• Max Takeoff Weight: 2,200 lbs

Loading Scenario:

• Pilot: 200 lbs
• Passenger: 180 lbs
• Baggage: 100 lbs (max for this compartment)
• Usable Fuel: 48 gallons (approx. 288 lbs)

Calculation Using the Free Aircraft Weight and Balance Calculator:

Inputs:

• Empty Weight: 1300 lbs
• Empty Weight CG: 7.5 in
• Forward Seat Weight: 200 lbs
• Forward Seat Arm: 32 in
• Aft Seat Weight: 180 lbs
• Aft Seat Arm: 54 in
• Baggage 1 Weight: 100 lbs
• Baggage 1 Arm: 81 in
• Fuel Weight: 288 lbs
• Fuel Arm: 38 in

Outputs:

• Total Weight: 1300 + 200 + 180 + 100 + 288 = 2068 lbs
• Total Moment: (1300 * 7.5) + (200 * 32) + (180 * 54) + (100 * 81) + (288 * 38) = 9750 + 6400 + 9720 + 8100 + 10944 = 44914 lb-in
• Current CG: 44914 lb-in / 2068 lbs = 21.72 inches from datum

Interpretation: The total weight (2068 lbs) is below the max takeoff weight (2200 lbs). However, the calculated CG (21.72 inches) is significantly outside the allowable limits (6.0 to 10.5 inches). This loading is unsafe. To correct this, the pilot would need to remove weight from the aft locations (like baggage or passengers) or add weight to the forward locations (if possible and allowed by the POH) until the CG is within limits. For instance, reducing baggage by 50 lbs and fuel by 50 lbs would decrease the CG, potentially bringing it into range. This demonstrates the critical importance of the CG calculation, not just total weight.

Our free aircraft weight and balance calculator helps identify such critical situations instantly.

How to Use This Free Aircraft Weight and Balance Calculator

Using our free aircraft weight and balance calculator is straightforward. Follow these steps to ensure accurate pre-flight calculations:

1. Select Aircraft Type: Choose your aircraft model from the dropdown. If 'Custom' is selected, you'll need to manually input the datum reference.
2. Enter Empty Weight and CG: Input the known Empty Weight (lbs) and its corresponding Center of Gravity (CG) arm (usually in inches from datum) from your aircraft's Pilot's Operating Handbook (POH) or Weight & Balance manual. Ensure you are consistent with the datum reference.
3. Input Occupant Details: Enter the weight of the pilot and any passengers. Then, input the arm (distance from datum) for each seating position (forward and aft). These arms are specific to the aircraft and found in the POH.
4. Add Baggage Weight and Arm: If you are carrying baggage, enter its weight and the arm of the respective baggage compartment. Most light aircraft have one or two baggage compartments with different arms.
5. Account for Fuel: Enter the weight of the *usable* fuel you plan to carry. Remember that fuel weight varies (e.g., ~6 lbs/gallon for Avgas, ~7 lbs/gallon for Jet A). Input the arm of the fuel tanks.
6. Click "Calculate": Once all relevant data is entered, click the "Calculate" button.

How to Read Results

• Primary Result (Current CG): This is the most important output, showing the calculated CG of your loaded aircraft. It will be displayed in the same units as your input arms (e.g., inches from datum).
• Empty Weight & CG Result: Shows the basic weight and CG of the aircraft before adding payload.
• Operating Weight & CG Result: Shows the total weight and CG after all occupants, baggage, and fuel are accounted for.
• CG Location Relative to Limits: This provides a quick status indicator (e.g., "Within Limits," "Forward of Limits," "Aft of Limits") based on the CG range specified in your aircraft's POH.
• Load Sheet Table: A detailed breakdown showing the weight, arm, and moment for each item, along with the total operating weight and total moment.
• Chart: The dynamic chart visualizes the aircraft's CG envelope (the acceptable range) and plots your current loading condition. This provides an intuitive understanding of your aircraft's stability.

Decision-Making Guidance

• Within Limits: If the calculated CG is within the forward and aft limits specified in the POH, and the total weight is below the maximum takeoff weight, your aircraft is loaded safely and legally for flight.
• Outside Limits: If the CG is outside the limits (too far forward or too far aft), you MUST adjust the load. This might involve redistributing baggage, reducing fuel, removing passengers, or, in some cases, adding ballast if permitted and necessary. Recalculate after making adjustments.
• Over Maximum Weight: If the total weight exceeds the maximum takeoff weight, you must remove weight until it is below the limit. This often means carrying less fuel, baggage, or fewer passengers.

Remember, always refer to your specific aircraft's POH for definitive weight and balance information and limits. This free aircraft weight and balance calculator serves as a powerful aid in this process.

Key Factors That Affect Aircraft Weight and Balance Results

Several factors significantly influence the accuracy and outcome of weight and balance calculations. Understanding these is key to safe operation:

1. Accuracy of Empty Weight and CG: The Empty Weight and its CG are the foundation of all subsequent calculations. If these figures are inaccurate (e.g., due to unrecorded modifications, equipment changes, or improper initial weighing), all other calculations will be skewed. Regular re-weighing is recommended, especially after major modifications.
2. Datum Reference Point: The location of the datum is critical. All arms must be measured consistently from this single point. A change in datum reference without corresponding arm adjustments will render calculations meaningless. POHs specify the datum clearly.
3. Weight of Occupants and Baggage: Using estimated weights for passengers and baggage can lead to inaccuracies. It's best practice to weigh occupants and baggage whenever possible, or use standard weights specified by aviation authorities (e.g., ~200 lbs per person in the US) if exact weights are unknown, while being mindful of baggage weight limits per compartment.
4. Fuel Load Calculation: Fuel weight is a significant variable. Errors in calculating fuel weight (e.g., incorrect density, miscounting gallons/liters) or using unusable fuel in the calculation will drastically affect the CG. Always calculate based on *usable* fuel and the correct density for the type of fuel being used.
5. Aircraft Modifications and Equipment Changes: Installing new avionics, structural modifications, or changing interior configurations alters the aircraft's empty weight and CG. These changes must be documented, and the empty weight and CG recalculated accordingly. Failure to do so can lead to dangerous miscalculations.
6. Arm Measurements Precision: The arms for seats, baggage compartments, and fuel tanks are fixed values found in the POH. Incorrectly applying these arms or measuring them inaccurately will directly impact the moment calculations and, consequently, the CG.
7. CG Envelope Limits: The allowable CG range (forward and aft limits) is determined by the aircraft's design and aerodynamics. Flying outside this envelope compromises stability and controllability. Exceeding these limits, even with a total weight below maximum, is a critical safety violation.
8. Variations in Equipment (e.g., different seats, larger baggage): If an aircraft has optional equipment or configurations (like different seat types or larger baggage compartments), ensure the arms and weights used in calculations correspond to the actual installed equipment.

The free aircraft weight and balance calculator aims to simplify these calculations, but the pilot remains responsible for inputting accurate data derived from the POH and actual loading.

Frequently Asked Questions (FAQ)

Q1: What is the difference between "moment" and "CG"?

A1: A moment (Weight x Arm) represents the leverage effect of a weight at a certain distance from the datum. The Center of Gravity (CG) is the calculated point where the aircraft's weight is balanced, determined by dividing the total moment by the total weight. Think of moment as the force trying to rotate the aircraft around the datum, and CG as the balance point.

Q2: Where do I find my aircraft's Empty Weight, CG, and CG Limits?

A2: This information is found in your specific aircraft's Pilot's Operating Handbook (POH) or Aircraft Flight Manual (AFM). It's typically located in the "Limitations" and "Weight and Balance" sections.

Q3: How often should I re-weigh my aircraft?

A3: While not always legally required for every flight, it's recommended to re-weigh your aircraft every few years or after significant modifications (like avionics upgrades, interior changes, or structural repairs) to ensure your empty weight and CG figures remain accurate.

Q4: What does "USABLE Fuel" mean in weight and balance calculations?

A4: Usable fuel is the amount of fuel that can be safely consumed by the engines during flight. Unusable fuel includes fuel in sumps, lines, and unusable tank portions. For weight and balance, you must always calculate based on the weight of the usable fuel only.

Q5: Can I put baggage in the passenger seats?

A5: Sometimes, but it depends entirely on the aircraft's POH. Often, baggage compartments have weight limits and specific arm measurements. Placing items in passenger seats might require you to treat them as passengers (with associated weight and arm) or might be prohibited. Always consult your POH.

Q6: What is the "Mean Aerodynamic Chord" (MAC)?

A6: MAC is the average chord length of the wing. Many aircraft list their CG limits as a percentage of MAC rather than inches from a datum. This provides a standardized way to express CG relative to the wing's aerodynamics, making it independent of the datum's location.

Q7: What happens if my CG is slightly outside the limits?

A7: Flying outside the CG limits, even slightly, is a serious safety issue. It can affect the aircraft's stability and controllability. You must adjust the load (fuel, passengers, baggage) to bring the CG back within the allowable range before flight. Consult your POH for specific guidance.

Q8: How does the 'Custom' aircraft type work in the calculator?

A8: When 'Custom' is selected, the calculator assumes you will manually input the datum reference and CG units. You are then responsible for ensuring the arms you enter correspond to that chosen datum, as defined in your aircraft's POH. The core calculation logic remains the same, but the reference frame is user-defined.

Q9: My calculated CG is very different from the CG of the empty aircraft. Is this normal?

A9: Yes, this is normal and expected. The CG shifts significantly with the addition of passengers, baggage, and fuel. The purpose of the weight and balance calculation is to determine the *new* CG of the aircraft in its current loaded configuration and verify it falls within the acceptable limits specified in the POH.

Related Tools and Internal Resources

• Aircraft Weight and Balance CalculatorUse our free tool for precise pre-flight calculations.
• Interactive CG Envelope ChartVisualize your aircraft's loading against its operational limits.
• Comprehensive Flight Planning ChecklistA detailed guide covering all aspects of preparing for a safe flight.
• Avgas Fuel Cost CalculatorEstimate your fuel expenses for upcoming trips.
• Aircraft Maintenance Logbook TemplateKeep accurate records of your aircraft's service history.
• Tips for Maintaining Pilot ProficiencyEnhance your flying skills and decision-making abilities.
• Understanding Aircraft Performance ChartsLearn to interpret charts for climb, cruise, and landing data.