Enter project parameters
Use this for capacity planning, tender notes, and equipment checks.
Formula used
How to use this calculator
- Enter LNG flow, then confirm the conversion factor from your LNG spec.
- Set efficiency and availability to match operations and maintenance plans.
- Fill operating hours and days to estimate annual throughput.
- Press Calculate capacity to show results above.
- Use Download CSV for logs and spreadsheets.
- Use Download PDF to save a printable report.
Example data table
| Scenario | LNG flow (m³/h) | Conv. (Nm³/m³) | Eff. (%) | Avail. (%) | Effective (Nm³/h) | Capacity (MMSCFD) |
|---|---|---|---|---|---|---|
| Site backup gensets | 40 | 600 | 97 | 90 | 20,952 | 17.76 |
| Mid-size industrial park | 120 | 600 | 98 | 95 | 67,032 | 56.81 |
| High send-out package | 250 | 610 | 98 | 96 | 143,472 | 121.60 |
Capacity inputs and assumptions
The calculator converts LNG volumetric flow to gas send-out using a configurable conversion factor, typically near 600 Nm³ per m³ LNG. Density is included to support mass flow checks (t/h) and to align with vendor datasheets. Enter efficiency and availability to reflect control losses, maintenance, boil-off handling, and vaporizer limits. For early estimating, 97–99% efficiency and 90–98% availability are common planning bands. Adjust inputs to match the selected vaporizer package rating.
Interpreting MMSCFD for site demand
MMSCFD is calculated from effective Nm³/h using 35.3147 scf per Nm³ and a 24-hour day. For construction utilities, compare MMSCFD with generator fuel curves, temporary boilers, asphalt plant consumption, and peak heating demand. Include a margin for start-up, purge, and transient loads during commissioning.
Annual throughput for contract planning
Annual throughput (million Nm³/year) uses your operating window in hours per day and days per year, so it can represent phased schedules. This supports budget forecasts, supply contracts, and storage turnover calculations. If operations are seasonal, reduce days/year to avoid overestimating delivered gas and logistics requirements.
Energy metrics and fuel switching
Energy throughput (MMBtu/day) multiplies effective gas flow by the selected MJ/Nm³ value and converts using 1055.056 MJ per MMBtu. This lets teams compare regas output with diesel displacement, burner ratings, and emissions reporting. A change from 37 to 41 MJ/Nm³ can shift MMBtu/day by over 10% at the same volumetric send-out. Use HHV or LHV consistently across procurement and reporting.
Quality checks and documentation
Use the example table to sanity-check magnitudes before issuing design notes. If results appear high, verify the conversion factor, units, and uptime assumptions, then confirm whether the project uses standard conditions or pipeline conditions. The sensible-duty line is a quick check only and does not represent full vaporization heat. Export CSV for audit trails and tender attachments, and save the PDF report for site documentation and approvals.
FAQs
What does the conversion factor represent?
It represents how many normal cubic meters of natural gas you obtain from one cubic meter of LNG after vaporization. Use your LNG composition or supplier documentation; typical planning values are around 580–620 Nm³ per m³ LNG.
Why include both efficiency and availability?
Efficiency captures process and control losses during operation, while availability captures downtime and maintenance. Multiplying both gives a realistic “effective” send-out rate for planning utilities, storage turnover, and contracted supply volumes.
Can I use this for terminal design?
It is suitable for preliminary estimates and comparisons, not final engineering. For detailed design, confirm standard conditions, pressure and temperature bases, vaporizer duty, boil-off management, and pipeline constraints using project specifications and vendor data.
What is the difference between Nm³/h and MMSCFD?
Nm³/h is a volumetric flow at normal conditions in metric units. MMSCFD is million standard cubic feet per day. The calculator converts using 35.3147 scf per Nm³ and assumes a 24-hour day.
How should I choose MJ/Nm³?
Use the heating value provided for your gas specification. Keep it consistent as HHV or LHV across calculations, procurement, and reporting. Small changes in MJ/Nm³ can noticeably change the MMBtu/day output.
Why is the duty estimate labeled “sensible” only?
It is a quick check based on warming LNG mass through a temperature rise. Real regasification duty is dominated by latent heat of vaporization and superheating requirements, so use dedicated thermal calculations for equipment sizing.