Enter the flow where it runs
Type the measured rate with its own volume and time units, then describe the operating point: actual temperature and pressure, in any units — gauge readings get an atmospheric correction.
Free tools · Industrial
One flow, every reference.
Actual, normal, standard or custom — convert gas flow between reference conditions with mixed units, computed on your device, never uploaded.
Actual · normal · standard · custom
One flow, every reference.
Enter the flow at its operating point, pick the reference you need — normal, a regional standard, or your own — and mix temperature, pressure, volume and time units freely. Everything computes on your device.
Input — what you measured
Output — what you need
How it works
Three steps, all on your device.
The same Boyle–Charles arithmetic behind every flow computer and DCS function block — with optional Standing–Katz compressibility — running here without accounts or uploads.
Pick the reference you need
Normal (0 °C), a regional standard (15 °C, 20 °C or 60 °F), or a fully custom temperature and pressure — with independent target volume and time units.
Read and copy
The converted rate appears with its full reference trail (source → target, ideal gas), ready to copy into datasheets, P&IDs and commissioning sheets.
Questions
Converting flow references, answered.
If you manage servers by hand, see the engineering services behind this tools series.
Is my data uploaded anywhere?
No. The conversion runs entirely in your browser — the page makes no network requests with your data. You can verify this in your browser's developer tools or disconnect from the network after the page loads.
What is the difference between actual, normal and standard flow?
Actual flow is the volume the gas really occupies at its operating temperature and pressure. Normal flow (Nm³/h) re-states that volume at 0 °C and 101.325 kPa absolute. Standard flow (Sm³/h) does the same at a regional standard — 15 °C in much of Europe, 20 °C in parts of industry, 60 °F in the US. Comparing flows only makes sense once they share a reference.
Which standard condition should I pick?
Match the document you are feeding: ISO 6976 natural-gas work in Europe almost always means 15 °C; airflow and process specs often use 20 °C; US gas contracts use 60 °F. When in doubt, ask which reference the datasheet or purchase order quotes — and use the custom reference if it names anything else.
Gauge or absolute pressure — which do I enter?
The math needs absolute pressure. If your gauge reads gauge (most field gauges), choose “Gauge (+ atmosphere)” and enter local atmospheric pressure — the tool adds it for you. Transmitters already compensated to absolute go in as “Absolute”.
Does it account for gas compressibility (Z-factor)?
Yes, optionally. Ideal gas (Z = 1) is the default and suits air near atmospheric conditions. For sweet natural gas at pressure, switch to the Standing–Katz model: pick methane, typical or heavy gas (or your own specific gravity) and the tool evaluates the Dranchuk–Abou-Kassem equation at both operating points. If you already know both factors — from a datasheet or another EOS — enter them as custom Z values instead.
Can I mix units, like °F with bar and CFM?
Yes. Temperature (°C, °F, K, °R), pressure (Pa through psi and atm), volume (m³, L, ft³, gallons, barrels) and time (seconds to days) convert independently on both sides, so field units in and datasheet units out is the normal way to use it.