Enter aircraft and mission inputs
Use SI units for all values. The form keeps a single-column page structure while the fields adapt to screen size.
Example data table
| Scenario | Weight (N) | Speed (m/s) | Angle (deg) | Total thrust (N) | Power (kW) | T/W |
|---|---|---|---|---|---|---|
| Regional turboprop climb | 85,000.00 | 72.00 | 5.0 | 18,031.51 | 1,298.27 | 0.2121 |
| Jet trainer cruise | 54,000.00 | 130.00 | 0.0 | 4,963.15 | 645.21 | 0.0919 |
| UAV accelerated climb | 2,200.00 | 34.00 | 8.0 | 1,088.91 | 37.02 | 0.4950 |
Formula used
The calculator estimates thrust required for steady or accelerating flight by combining aerodynamic drag, climb demand, and longitudinal acceleration demand.
T = D + W sin(γ) + (W / g) a
Drag is built from a classic parabolic drag polar:
CD = CD0 + k CL2
D = q S CD + Dextra, where q = 0.5 ρ V2
Lift coefficient is estimated from the lift needed along the flight path:
CL = [W cos(γ)] / (q S)
Where T is thrust, D is drag, W is aircraft weight, γ is flight path angle, a is longitudinal acceleration, ρ is air density, V is speed, S is wing area, CD0 is zero-lift drag coefficient, and k is induced drag factor.
How to use this calculator
- Enter aircraft weight as force in newtons.
- Provide flight speed, wing area, and air density.
- Enter aerodynamic coefficients CD0 and k from your design data.
- Set climb angle and longitudinal acceleration for the mission segment.
- Add extra drag for stores, landing gear, or configuration penalties.
- Choose engine count and a reserve thrust margin.
- Press the calculate button to display the result above the form.
- Download the result as CSV or PDF for design reviews.
Frequently asked questions
1. What does thrust required mean?
It is the total propulsive force needed to overcome drag and satisfy climb or acceleration demands for a chosen flight condition. Designers use it to size engines and compare mission segments.
2. Should I enter weight or mass?
Enter weight as force in newtons. If you only know mass, multiply it by gravitational acceleration first. The calculator internally converts weight back to mass only for acceleration force.
3. How is climb included?
The climb term uses W sin(γ). A positive flight path angle increases required thrust, while a negative angle reduces it. This is a standard steady-flight approximation.
4. What is the induced drag factor?
It is the coefficient that scales drag created by lift. Higher values usually reflect lower aspect ratio wings or poorer aerodynamic efficiency. It strongly affects low-speed thrust requirements.
5. Why is air density important?
Air density changes dynamic pressure at the same speed. Lower density can raise required lift coefficient, alter drag, and shift the thrust needed for the same mission segment.
6. Can I use this for propeller or jet aircraft?
Yes. The output is thrust demand, not engine type. You can use it for propeller, electric, or jet studies, then map the result to available propulsion performance.
7. Why add a thrust margin?
A margin helps cover model uncertainty, off-design operation, installation losses, or future growth. It is useful during preliminary sizing, trade studies, and conservative requirement checks.
8. When should I use a more detailed model?
Use a higher-fidelity model for large climb angles, rapid maneuvering, compressibility effects, thrust lapse analysis, or full mission simulations. This calculator is best for conceptual and preliminary engineering work.