How to use the sound speed calculator
Prepare the values for this calculation
Calculate ideal-gas sound speed from γ, specific gas constant and absolute temperature. 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
- Heat-capacity ratio γ: enter a value at least 1e-12. Use the unit named in the label or selected above. Do not leave this required field blank.
- Specific gas constant (J/kg·K): enter a value at least 1e-12. Use the unit named in the label or selected above. Do not leave this required field blank.
- Absolute temperature (K): enter a value at least 1e-12. 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 Ideal-gas sound speed first. With the unchanged example inputs, it is 343.23197768 m/s. 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 Heat-capacity ratio γ from 1.4 to 1.54. The resulting Ideal-gas sound speed is 359.98473516 m/s. 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.
Sound Speed Calculator formula
a=√(γRT).
Inputs and units
| Input | Format / range | Example |
|---|---|---|
| Heat-capacity ratio γ | minimum 1e-12 | 1.4 |
| Specific gas constant (J/kg·K) | minimum 1e-12 | 287.05 |
| Absolute temperature (K) | minimum 1e-12 | 293.15 |
Worked example
Using the example inputs above, the ideal-gas sound speed is 343.23197768 m/s.
- Ideal-gas sound speed
- 343.23197768 m/s
Results and assumptions
Ideal-gas sound-speed model.
Fix an input or unexpected result
Heat-capacity ratio γ is required. Enter heat-capacity ratio γ 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.