Wing Loading Calculator
Every aircraft design process begins with the wing loading calculation. Wing loading is a parameter that affects several performance characteristics of an aircraft, such as its speed during take-off, landing, cruising, and stalling. Wing loading depends on only two factors — the weight and the projected area of the wings — yet it also influences the turning performance and stability of an aircraft. Read on to understand what wing loading is and how to use the wing loading formula to get started with any aircraft design process.
Our surface area calculator (for the area of different wing shapes) and weight converter might be useful before using this tool.
What is the wing loading parameter?
Wing loading is defined as the ratio of the weight of an aircraft to the projected area of its wings. The weight here is usually taken as the gross weight or maximum take-off weight of the aircraft. The wing loading parameter WL is given by the equation:
WL = W / S
where W and S are the weight of the aircraft and the wing area. In other words, wing loading can be thought of as the weight of the aircraft per unit area of wing, like a surface density. Similarly, the wing cube loading WCL can be written as:
WCL = W / S1.5
Wing loading is measured in units of kg/m² and lb/ft², whereas wing cube loading is measured as weight per unit volume, i.e., the same units as density (kg/m³ or lb/ft³). You can also explore a thrust-to-weight ratio calculator to help you design an aircraft.
Parameters affected by wing loading
The wing loading parameter forms the basis of the early stages of aircraft design. Some of the parameters affected by the value of wing loading are:
- Aircraft speeds — Different types of aircraft speeds, such as take-off and landing speeds, cruising and maximum speeds, and stalling speed, are all affected by any change in wing loading. The wing area remains constant, which implies that the load carried by the aircraft causes the increase and decrease of the various speeds. For a given velocity V:
WL ∝ V²
- Turning performance — The turning radius and load factor depend on wing loading. An aircraft can make tighter turns if its weight is lower. For a particular turning radius R:
WL ∝ R
How to calculate wing loading using this calculator?
- Choose your measurement system — Metric (kg, m²) or American/Imperial (lb, ft²).
- Enter the weight of the aircraft.
- Fill in the wing area.
- The wing loading calculator will return both the wing loading and the wing cube loading in metric and imperial units.
You can also pick a sample aircraft (such as the MiG-21, Cessna 172, F-16, Boeing 747 or a glider) from the quick presets to instantly fill in both its wing area and weight.
Example: Using the aircraft wing loading calculator
Estimate the wing loading for a MiG-21 aircraft whose wing area is 23 m² and take-off weight is 10,400 kg.
To calculate wing loading:
- Fill in the wing area: S = 23 m².
- Enter the weight of the aircraft: W = 10,400 kg.
Using the wing loading formula:
WL = W / S = 10400 / 23 = 452.2 kg/m²
Similarly, the wing cube loading can be calculated as:
WCL = W / S1.5 = 10400 / 231.5 = 94.28 kg/m³
Wing loading for aircraft
The wing loading parameter varies for different types of aircraft. For instance, a glider has a very low wing loading compared with a military or passenger jet. Similarly, a passenger aircraft has a larger wing loading than a military fighter due to its larger load. Different wing configurations also have different aspect ratios and wing loadings. A typical hobby RC aircraft has a wing loading of about 0.625–2.5 lb/ft².
FAQs
What is wing loading?
Wing loading is the ratio of an aircraft's weight to its wing area (WL = W / S). It indicates how much weight each unit of wing area must support and strongly influences take-off, landing, cruise and stall speeds.
What is wing cube loading?
Wing cube loading is the weight divided by the wing area raised to the power 1.5 (WCL = W / S1.5). Because it has units of density, it is useful for comparing models of different sizes, especially in RC aircraft.
How does wing loading affect flight?
Higher wing loading generally means higher speeds and a smoother ride in turbulence but also higher stall and landing speeds. Lower wing loading allows slower, more maneuverable flight and shorter take-off and landing distances, which is why gliders have very low wing loading.
What are typical wing loading values?
Hobby RC aircraft: ~0.6–2.5 lb/ft²; light general-aviation aircraft: ~10–20 lb/ft²; military fighter jets: often 50–120 lb/ft²; large passenger jets: well above 100 lb/ft².