Signal Converter Calculator (4–20 mA ↔ 0–10 V ↔ 1–5 V)

How to use the signal converter calculator

Enter a value in any one field — a 4–20 mA current, a percent of range or one of the voltage signals — and the calculator fills in the equivalent value for every other standard. All conversions are linear by percent of range.

Signal conversion formulas

% = (I_4–20 − 4 mA) ÷ 16 mA

I_0–20 = 20 mA × %  ·  V_0–10 = 10 V × %  ·  V_1–5 = 1 V + 4 V × %  ·  V_0–5 = 5 V × %

Example

12 mA on a 4–20 mA loop:

• Percent = (12 − 4) ÷ 16 = 50%
• 0–20 mA = 10 mA, 0–10 V = 5 V, 1–5 V = 3 V, 0–5 V = 2.5 V

Signal conversion table

% of range	4–20 mA	0–20 mA	1–5 V	0–10 V
0%	4.00 mA	0.00 mA	1.00 V	0.00 V
10%	5.60 mA	2.00 mA	1.40 V	1.00 V
25%	8.00 mA	5.00 mA	2.00 V	2.50 V
50%	12.00 mA	10.00 mA	3.00 V	5.00 V
75%	16.00 mA	15.00 mA	4.00 V	7.50 V
90%	18.40 mA	18.00 mA	4.60 V	9.00 V
100%	20.00 mA	20.00 mA	5.00 V	10.00 V

Choosing a signal

• 4–20 mA is immune to voltage drop along the cable, detects a broken wire and can power 2-wire transmitters — the plant standard.
• 0–10 V is common for drives, dampers and building automation over short distances.
• 1–5 V is the voltage across a 250 Ω resistor in a 4–20 mA loop and is how many controllers read current inputs.

Frequently asked questions

How do I convert 4–20 mA to 0–10 V?

Find the percent of range, (mA − 4) ÷ 16, then multiply by 10 V. 12 mA is 50%, which is 5 V.

How do I convert 4–20 mA to 1–5 V?

Pass the current through a precision 250 Ω resistor — 4 mA gives 1 V and 20 mA gives 5 V. This is how many DCS and PLC voltage inputs read current loops.

Can I convert 0–10 V to 4–20 mA with a resistor?

No. Converting voltage to a current loop needs an active converter or isolator that drives a controlled current. Going from current to voltage only needs a resistor.

Why is 4 mA used instead of 0 mA?

A live zero lets the receiver tell a 0% signal from a broken wire (0 mA), and leaves enough current to power 2-wire transmitters.

Related calculators

• 4–20 mA Scaling CalculatorConvert a 4–20 mA loop current to a process value (and back) for any measuring range — with live scaling chart.
• PLC Analog Scaling Calculator (Raw Counts to Engineering Units)Convert PLC analog input raw counts to engineering units and back — for Siemens 0–27648, 0–4095, 0–32767 and any custom raw range.
• 4–20 mA Loop Resistance Calculator (Maximum Loop Load)Check whether a 4–20 mA loop has enough voltage — maximum loop resistance from supply and transmitter lift-off voltage, with cable and barrier resistance.
• Voltage Divider CalculatorCalculate the output voltage of a resistor voltage divider, or the resistor values needed for a target output — with divider current and power.
• 5-Point Calibration Calculator (0–25–50–75–100% Table)Generate a 5-point calibration table for any transmitter — input values and expected 4–20 mA (or other) outputs at 0, 25, 50, 75 and 100% of range.
• Mass Flow Rate CalculatorConvert volumetric flow to mass flow and back using fluid density — kg/h, t/h, lb/h, m³/h, L/min and more.

Embed this calculator