Wing Weight Calculator
Professional Aerospace & RC Weight Estimation Tool
Estimate Wing Mass
Estimated Wing Weight
Solidity Sensitivity Analysis
Weight Breakdown Estimation
| Component | Est. Percentage | Est. Mass (kg) |
|---|
What is Calculate Wing Weight?
The process to calculate wing weight is a fundamental step in aerospace engineering and aeromodelling design. It involves determining the total mass of an aircraft's lifting surface based on its geometry, material properties, and internal structural composition. Accurate weight estimation is critical because the wing must be strong enough to support the fuselage and payload while being light enough to ensure efficient flight characteristics.
Whether designing a General Aviation (GA) aircraft, a UAV, or a radio-controlled (RC) plane, understanding how to calculate wing weight allows designers to optimize the "Strength-to-Weight" ratio. Engineers use this calculation to predict the aircraft's Center of Gravity (CG) and determine the necessary lift coefficient required for takeoff.
Common misconceptions include assuming wings are solid blocks of material or that surface area alone determines weight. In reality, the internal structure (ribs, spars, skin thickness) and the airfoil's volume play the most significant roles in the final mass.
Wing Weight Formula and Mathematical Explanation
To calculate wing weight accurately without complex CAD software, engineers often use a geometric volume estimation method adjusted by a solidity factor. The core logic relies on determining the volume of the wing and applying the density of the construction materials.
The Geometric Approximation Formula
The simplified formula used in our calculator is derived as follows:
Weight = Volume × Material Density × Solidity Factor
Where Volume is approximated by treating the wing as a prism with an airfoil cross-section:
Volume ≈ Span × Mean Chord × (Mean Chord × ThicknessRatio) × AirfoilShapeFactor
Variables Table
| Variable | Meaning | Unit | Typical Range |
|---|---|---|---|
| b | Wing Span | meters (m) | 0.5m (RC) – 30m+ (Transport) |
| c | Mean Chord | meters (m) | 0.1m – 3.0m |
| t/c | Thickness Ratio | Percentage (%) | 8% (Fast) – 18% (Slow/Cargo) |
| ρ (rho) | Density | kg/m³ | 30 (Foam) – 2700 (Aluminum) |
| η (eta) | Solidity/Fill Factor | Percentage (%) | 10% (Built-up) – 100% (Solid Core) |
Practical Examples (Real-World Use Cases)
Example 1: RC Glider (Balsa Built-up Wing)
An RC hobbyist wants to calculate wing weight for a new thermal glider. The wing uses a rib-and-spar construction method.
- Span: 2.0 meters
- Mean Chord: 0.2 meters
- Thickness: 10%
- Material: Balsa Wood (160 kg/m³)
- Solidity: 15% (Mostly air inside, just ribs and covering)
Result: The calculated weight would be approximately 0.13 kg (130 grams). This confirms the glider will be lightweight and suitable for catching thermals.
Example 2: Foam Core UAV Wing
A university team is designing a drone with a solid foam core wing reinforced with tape.
- Span: 1.5 meters
- Mean Chord: 0.3 meters
- Thickness: 14%
- Material: XPS Foam (50 kg/m³)
- Solidity: 100% (Solid block cut with hot wire)
Result: The wing volume is substantial due to the thickness and solid core. The estimated weight is roughly 0.66 kg (660 grams) excluding the motor mount, which helps the team size their servo motors correctly.
How to Use This Wing Weight Calculator
- Enter Geometry: Input the total Wing Span and the Mean Chord (average width). If you have a tapered wing, calculate the average of the root and tip chords.
- Set Thickness: Input the airfoil thickness percentage. Thicker wings create more lift but add volume and drag.
- Select Material: Choose a preset material like Balsa or Foam, or select "Custom" to enter a specific density.
- Estimate Solidity:
- Use 90-100% for solid foam wings.
- Use 15-25% for built-up balsa wings (ribs and covering).
- Use 5-10% for hollow molded composite wings.
- Analyze Results: Use the "Copy Results" button to save the data for your design log. Check the chart to see how reducing solidity (hollowing out the wing) could save weight.
Key Factors That Affect Calculate Wing Weight Results
When you calculate wing weight, several physical and design factors influence the final number. Understanding these can help you optimize your aircraft design.
1. Aspect Ratio
High aspect ratio wings (long and skinny like a glider) are structurally more demanding. To prevent bending, they often require heavier spars, effectively increasing the "Solidity" factor required to maintain structural integrity.
2. Material Selection
The choice between Balsa (160 kg/m³) and Aluminum (2700 kg/m³) is drastic. However, aluminum is much stronger, allowing for much thinner skins (lower solidity). A balsa wing might be 20% solid, while an aluminum wing might effectively be only 2% solid volume due to hollow construction.
3. Airfoil Thickness
A thick wing (e.g., 18%) has much more internal volume than a thin wing (e.g., 8%). While a thick wing is lighter to build structurally (due to better leverage for the spar), the geometric volume increases, which can increase the weight if using a solid core.
4. Structural Load Factor (G-Loading)
Wings designed for aerobatics (high G-force) need internal reinforcements. This increases the solidity factor. A Piper Cub wing is lighter per square meter than an F-16 wing partly because the F-16 must withstand 9G maneuvers.
5. Manufacturing Technique
A "bagged" composite wing might use excess epoxy resin, adding unnecessary weight. This is represented in the calculator by increasing the material density or the solidity percentage slightly to account for glue weight.
6. Taper Ratio
Tapered wings (narrower at the tip) reduce the volume and weight at the tips, which reduces the structural moment at the root. This allows for a lighter spar structure overall compared to a rectangular wing of the same area.
Frequently Asked Questions (FAQ)
No. This tool is designed to calculate wing weight for the airframe structure only. You must add the weight of electronics, wiring, and propulsion systems separately to get the All-Up Weight (AUW).
For a simple trapezoidal wing, the Mean Aerodynamic Chord (MAC) is roughly the average of the Root Chord and Tip Chord: (Root + Tip) / 2.
Wings are rarely solid blocks. A "built-up" wing is mostly air. If you ignore solidity and calculate based on solid volume, your weight estimate will be 5 to 10 times too high.
This calculator provides a geometric estimation useful for preliminary design. Certified aircraft weight requires strict adherence to manufacturer data and regulatory weighing procedures.
For RC trainers, 4-6 kg/m² (converted to oz/sq ft) is good. For fast jets, it can be much higher. The lighter the wing structure calculated here, the more payload you can carry.
Yes. A "flat bottom" airfoil generally has more volume than a symmetrical one of the same thickness percentage. We use a shape factor of 0.7 as a general average.
Carbon is heavy (high density) but extremely strong. You would select a high density but a very low solidity factor (e.g., 2-5%) because the skins can be paper-thin.
Aerospace engineering predominantly uses metric units for simplified calculations of mass and density. However, 1 kg ≈ 2.2 lbs if you need to convert.
Related Tools and Internal Resources
- Wing Loading Calculator – Determine if your aircraft has enough wing area for its weight.
- CG (Center of Gravity) Calculator – Find the balance point using your new wing weight data.
- Airfoil Section Database – Compare thickness ratios of standard NACA airfoils.
- Thrust to Weight Ratio Calculator – Check if your motor is powerful enough.
- RC Plane Flight Time Calculator – Estimate battery duration based on weight and drag.
- Material Density Chart – Comprehensive list of aerospace material densities.