4-20 mA Scaling Calculator
Convert between milliamps, percent and engineering units for any range, with the raw PLC count.
Free. No sign-up. Runs entirely in your browser, so nothing you type is uploaded or stored.
Current
12 mA
Percent of span
50 %
Value
5 bar
Raw count
13,824
Formula: value = low + (mA − 4) ÷ 16 × (high − low). Raw ranges differ by card and configuration; check your module's manual.
How to use it
- 1Enter the range your transmitter is set to: the value at 4 mA and at 20 mA.
- 2Choose which way you are converting, and type the number.
- 3Pick your analog card to see the raw count the PLC reads.
- 4Below 3.8 mA or above 20.5 mA usually means a fault, not a reading.
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