Calculate turbojet and turbofan gross thrust, net thrust, ram drag, and bypass thrust distribution across flight speeds.
Did this calculation save you time?
Student ProjectHi! I'm a student developer building Calculat in my spare time. I was tired of searching for basic math tools and having to click through 10 spammy popups, loan ads, and cookie trackers.
I keep this website 100% free, private, and ad-free. If this helped you with your homework, project, or finances today, bookmarking this page or telling a friend helps me keep building more free tools!
The Jet Engine Thrust Calculator evaluates the net forward thrust produced by air-breathing turbojet and turbofan engines. By accounting for air mass flow, fuel flow, exhaust velocity, aircraft flight velocity (ram drag), and bypass ratio, it determines total installed propulsive force.
F_{\text{net}} = (\dot{m}_{\text{air}} + \dot{m}_{\text{fuel}}) v_{\text{exit}} - \dot{m}_{\text{air}} v_0Where gross thrust is exhaust momentum and ram drag (m_air * v_0) represents the momentum penalty of capturing incoming ambient air at flight speed v_0.
Scenario: A turbofan ingesting 200 kg/s of air with an exhaust velocity of 400 m/s flying at 150 m/s (Mach 0.45) with a 5:1 bypass ratio.
Gross Thrust: ~204 kg/s × 400 m/s = 81.6 kN.
Ram Drag: 200 kg/s × 150 m/s = 30.0 kN.
Net Thrust: 81.6 - 30.0 = 51.6 kN (~11,600 lbf).
Fan Bypass Share: 5 / (1 + 5) = 83.3% of total thrust produced by the fan.
The bypass ratio is the mass of air that passes through the fan duct around the engine core divided by the mass of air that enters the core combustion chamber.
Ram drag is the retarding momentum force incurred by the engine when scooping up stationary ambient air and accelerating it to the forward speed of the aircraft.
A GE90-115B engine on a Boeing 777 produces up to 115,000 lbf (512 kN) of thrust, making it one of the most powerful jet engines ever built.
TSFC stands for Thrust Specific Fuel Consumption. It measures fuel mass burned per unit of thrust per hour (e.g. kg of fuel per kN of thrust per hour). Lower TSFC indicates better fuel efficiency.
Calculate rocket propulsion thrust, specific impulse (Isp), effective exhaust velocity, and pressure thrust across atmosphere and vacuum.
Calculate mechanical, aerodynamic, and momentum thrust from fluid mass flow rate, exhaust velocity, and pressure differential.
Calculate Thrust-to-Weight Ratio (TWR), vertical acceleration in G-forces and m/s², and flight capability for rockets, aircraft, and drones.