SCADA, RTU & HMI calculator
Analog Scaling Calculator
Scale raw PLC, RTU or SCADA analog values to engineering units, or convert an engineering value back to raw counts.
SCADABasis: Linear instrumentation scaling
Results
- Enter values to calculate
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Formula
EU = EUmin + (Raw − Rawmin) · (EUmax − EUmin) / (Rawmax − Rawmin)
Raw = Rawmin + (EU − EUmin) · (Rawmax − Rawmin) / (EUmax − EUmin)
Worked example
For 0–32767 counts mapped to 0–100 psi, a raw value of 16384 is approximately 50.0 psi.
Assumptions and standards
- Linear scaling only.
- Raw and engineering spans must be non-zero.
- Use the transmitter or RTU channel limits actually configured in the device; some systems reserve counts for underrange or overrange diagnostics.
Formula and data last verified: October 2026.
Frequently asked questions
Can I use this for 4–20 mA signals?
Yes if your input module converts 4–20 mA to a known raw-count range. Enter that module raw range and the transmitter engineering range.
Why is my raw range not 0–32767?
Different PLC and RTU families use different integer ranges and may reserve counts for diagnostics. Use the values from the module configuration or manual.
Can I use these results for final design?
Use them for preliminary design and checking. Final designs must be verified by a qualified engineer against the code edition and standards adopted where the work is installed.
Is my data sent anywhere?
No. Every calculation runs in your browser. Nothing you type is uploaded or stored on our servers.