How to use the jet engine calculator
Prepare the values for this calculation
Calculate one-dimensional steady jet thrust from momentum and pressure terms. Use the formula below to check that it answers your question. Read the input units before transferring figures from a statement, measurement or dataset.
Enter and check each input
- Mass flow ṁ (kg/s): enter a value at least 0. Use the unit named in the label or selected above. Do not leave this required field blank.
- Exit velocity Ve (m/s): enter a finite number. Use the unit named in the label or selected above. Do not leave this required field blank.
- Flight velocity V0 (m/s): enter a finite number. Use the unit named in the label or selected above. Do not leave this required field blank.
- Exit pressure pe (Pa): enter a finite number. Use the unit named in the label or selected above. Do not leave this required field blank.
- Ambient pressure p0 (Pa): enter a finite number. Use the unit named in the label or selected above. Do not leave this required field blank.
- Exit area Ae (m²): enter a value at least 0. Use the unit named in the label or selected above. Do not leave this required field blank.
The input table gives a complete example. Keep units and time periods consistent across related fields.
Calculate and resolve any input error
Choose Calculate after entering the values. Changes also update the answer after a short pause. If an error appears, follow its message, correct the field and calculate again. Reset restores the example values.
Interpret the answer
Check Net thrust first. With the unchanged example inputs, it is 20,000 N. Interpret it using the formula and assumptions on this page.
Compare and keep a useful result
For a controlled comparison, keep every other example input unchanged and change Mass flow ṁ (kg/s) from 50 to 55. The resulting Net thrust is 22,000 N. This illustrates the equation’s response to that input, rather than a forecast of real events.
Read the chart’s axis labels and data table. A scenario curve changes one stated input while holding the others fixed; it does not add external observations. Use Download graph to save an available chart as a PNG.
Use Copy result or Download CSV to keep the answer. Share tool shares the page address without placing your input values in the URL. Recheck inputs and assumptions before using the result for a decision.
Jet Engine Calculator formula
F=ṁ(Ve−V0)+(pe−p0)Ae.
Inputs and units
| Input | Format / range | Example |
|---|---|---|
| Mass flow ṁ (kg/s) | minimum 0 | 50 |
| Exit velocity Ve (m/s) | Number | 600 |
| Flight velocity V0 (m/s) | Number | 200 |
| Exit pressure pe (Pa) | Number | 101325 |
| Ambient pressure p0 (Pa) | Number | 101325 |
| Exit area Ae (m²) | minimum 0 | 0.5 |
Worked example
Using the example inputs above, the net thrust is 20,000 N.
- Net thrust
- 20,000 N
Results and assumptions
One-dimensional steady thrust equation; inlet pressure drag and installation effects are omitted.
Fix an input or unexpected result
Mass flow ṁ (kg/s) is required. Enter mass flow ṁ (kg/s) using the format and bounds in the input table. Zero and an empty field are different: use zero only if it is allowed and represents your data.
If your answer differs from the example, choose Reset and compare every field, including selected units and options. Check percentage versus decimal entry and whether values describe the same period. Round only the final displayed answer when reproducing the formula.
If a discrepancy remains, report the calculator issue with the page address, non-sensitive example inputs, actual result, expected result and a reference for your calculation.