Calculate TSFC
Switch between a quick basic calculation and the full advanced propulsion analysis mode.
Interactive Analysis Graphs
Generated live from your Advanced Mode inputs. Run the analysis above to populate.
TSFC vs Thrust
Sensitivity of TSFC as net thrust varies, fuel flow held constant.
TSFC vs Altitude
Approximate trend as ambient temperature falls with altitude.
TSFC vs Mach Number
Illustrative TSFC trend across the flight Mach range.
Fuel Burn Rate
Fuel burn per hour, per kilometre, and per nautical mile.
Aircraft Range Sensitivity
Estimated range as available fuel weight changes.
Engineering Reference Tables
Typical values used to sanity-check a calculation against real hardware.
| Engine Type | Typical TSFC (lb/lbf·hr) | Typical TSFC (kg/N·hr) | Notes |
|---|
| Aircraft | Engine | Cruise TSFC (lb/lbf·hr) | Category |
|---|
| Fuel | Density (kg/m³) | Heating Value (MJ/kg) | Energy Content (MJ/L) |
|---|
How Engineers Use TSFC
Practical applications across the aircraft lifecycle.
Engine Comparison Module
Compare TSFC, fuel burn, and range impact across three engines side by side.
Engine A
Engine B
Engine C
| Engine | TSFC (kg/N·hr) | Fuel Burn (kg/hr) | Relative Efficiency | Range Impact |
|---|
Scenario Simulator
One-click presets that populate Advanced Mode with representative values.
Understanding TSFC
Grounding for students and anyone new to propulsion performance metrics.
Formula Library
The core equations behind this calculator, with short derivations.
Variables
| Symbol | Quantity | Unit |
|---|---|---|
| TSFC | Thrust specific fuel consumption | kg/(N*s) |
| mdot_f | Fuel mass flow rate | kg/s |
| T | Thrust | N |
What it means
TSFC is a key engine performance parameter, indicating how much fuel is consumed per unit thrust. It is typically expressed in kg/(N·s) or lb/(lbf·h). Lower TSFC means better fuel economy. TSFC varies with altitude, speed, and throttle setting. It is used in the Breguet range equation and in mission analysis. Understanding TSFC is essential for comparing engines and for evaluating propulsion system efficiency.
Worked example
TSFC – Two Examples
Real‑World| Parameter | Value |
|---|---|
| ṁ_f | 0.36 kg/s |
| T | 20,000 N |
| Parameter | Value |
|---|---|
| ṁ_f | 0.5 |
| T | 25,000 |
Common mistakes
- Thrust specific fuel consumption: TSFC = ṁ_f / T.
- Units: kg/(N·s) or 1/s (since N = kg·m/s², so kg/(N·s) = kg/(kg·m/s²·s) = s/m? Actually, TSFC is typically given in kg/(N·h) or lb/(lbf·h). In SI, it’s kg/(N·s).
- Lower TSFC means better fuel efficiency.
- Typical values: 0.5‑0.9 lb/(lbf·h) for turbofans.
Applications
Thrust specific fuel consumption (TSFC), TSFC = ṁ_f / T, is the fuel flow rate per unit thrust, a measure of engine efficiency. Lower TSFC means less fuel for a given thrust, leading to better range and endurance. Engineers use TSFC to compare engines, to design propulsion systems, and to predict mission performance. It is a key parameter in the Breguet equations. By reducing TSFC through advanced cycles and materials, aerospace engineers can improve aircraft efficiency and reduce emissions.
- Engine selection and performance comparison
- Mission performance prediction (range, endurance)
- Propulsion system design and optimisation
- Technology roadmapping for next‑generation engines
- Economic and environmental analyses
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