Engineering / 01
4–20 mA Calculator
Convert a 4–20 mA current signal into an engineering value, or calculate the current for a specified value.
How it works
value = lower + (mA − 4) / 16 × (upper − lower).
mA = 4 + (value − lower) / (upper − lower) × 16.
For a 0–100 bar range, 4 mA represents 0 bar, 12 mA represents 50 bar, and 20 mA represents 100 bar. Each direction has its own range inputs; the unit label applies to both.
FAQ
Can I use units other than bar?
Yes, enter the label for your engineering unit, such as °C, mm, or psi. The scale is linear and does not convert between physical units.
What happens outside 4–20 mA?
The calculator extrapolates the same straight line and displays a range notice. It does not interpret transmitter faults, alarms, or sensor-specific behavior.
Why must the upper range exceed the lower range?
This tool uses an increasing scale with a nonzero span. Equal or reversed limits display a message so you can correct the range.