In this Lift Coefficient calculator, we will show you how to find the lift coefficient in just a few seconds.
We will also help you understand the lift coefficient definition, and the lift formula while we’re at it.
How does it depend on lift force, airspeed, air density, and wing area?
How do engineers use it for airplanes, drones, and helicopters?
How to calculate lift coefficient step by step? Find all the answers here and learn with examples, reference tables, and a handy calculator.
Lift Coefficient Calculator
Lift Coefficient (CL) Explained
The lift coefficient (CL) is a dimensionless number that describes how efficiently a wing or airfoil generates lift. It is calculated using the formula:
CL = L / (0.5 × ρ × V² × S)
Where:
- CL = Lift Coefficient (dimensionless)
- L = Lift Force (Newtons, N)
- ρ = Air Density (kg/m³), about 1.225 kg/m³ at sea level
- V = Air Velocity (m/s)
- S = Wing Planform Area (m²), as seen from above
- 0.5 × ρ × V² = Dynamic Pressure (q)
Real-World Applications of Lift Coefficient
| Application | Explanation |
|---|---|
| Aircraft Wings | Used to calculate required lift for takeoff, cruise, and landing performance. |
| Helicopter Rotor Blades | Helps determine how much lift each rotor blade generates at different speeds and angles of attack. |
| Wind Turbines | Lift coefficient helps optimize blade shape for maximum energy generation. |
| Formula 1 Cars / Race Cars | Used in designing spoilers and wings to generate downforce, improving tire grip and cornering. |
| Drone Propellers | Helps engineers design efficient propellers for stable flight and load carrying. |
Example Problem
Problem Statement: A small airplane generates a lift force of 12,000 N at a velocity of 50 m/s. The wing area is 20 m² and the air density at sea level is 1.225 kg/m³. Calculate the lift coefficient CL for this flight condition.
Step-by-Step Solution
- Lift Force, L = 12,000 N
- Air Density, ρ = 1.225 kg/m³
- Air Velocity, V = 50 m/s
- Wing Area, S = 20 m²
Dynamic pressure, q = 0.5 × ρ × V²
q = 0.5 × 1.225 × 50² = 0.6125 × 2500 = 1531.25 Pa
CL = L / (q × S)
CL = 12,000 / (1531.25 × 20) = 12,000 / 30,625 ≈ 0.3916
The lift coefficient for this condition is:
CL ≈ 0.392
Reference Cards for Lift Calculations
Air Density (ρ)
Typical Values: 1.225 (Sea Level), 1.112 (1 km), 1.007 (2 km)
Units: kg/m³
Notes: Decreases with altitude; standard atmosphere
Wing Planform Area (S)
Typical Values: 16 – 50
Units: m²
Notes: Small planes: ~16–30 m²; medium planes: ~30–50 m²
Lift Force (L)
Typical Values: 5,000 – 200,000
Units: N
Notes: Varies by aircraft size
Air Velocity (V)
Typical Values: 40 – 250
Units: m/s
Notes: Typical cruise velocities for small to medium aircraft
Typical CL Values
Range: 0.3 – 1.8
Units: Dimensionless
Notes: Depends on wing design, airfoil, and angle of attack
Dynamic Pressure (q)
Formula: q = 0.5 × ρ × V²
Typical Values: 100 – 50,000
Units: Pa
Notes: Calculated using air density and velocity
FAQs
What is lift coefficient?
In this calculator, we will show you how to find the lift coefficient in seconds. The lift coefficient is a number that tells us how efficiently a wing or airfoil generates lift.
Why is lift coefficient important?
It helps engineers design wings, propellers, and aircraft so they produce enough lift for safe flight.
What factors affect lift coefficient?
Air speed, air density, wing area, and angle of attack all change CL.