4–20 mA Burden Voltage
V_burden = I × R
Quick answer
This calculator solves V_burden = I_loop × R_burden for Burden Voltage. With Loop Current 20 mA, Burden Resistance 0.47 kΩ, the result is 9.4 V. It solves in 3 directions, so you can enter the values you have and get the one you need.
Calculator
Formula
Description
In a 4-20 mA current loop, the receiving device (PLC, DCS, or indicator) converts the current signal to a voltage by passing it through a precision burden resistor. The voltage across this resistor is what the ADC actually measures. A standard 250Ω burden produces 1-5V from the 4-20 mA signal, which is a convenient range for many ADC inputs. The total burden of all devices in the loop must not exceed the transmitter compliance voltage, or the loop current will be unable to reach 20 mA.
Variables
- V — Voltage across the burden resistor (V)
- I — Loop current (A)
- R — Burden resistance (Ω)
Practical Notes
Common burden values: 250Ω for 1-5V output, 500Ω for 2-10V output. The loop power supply must provide enough voltage to overcome all burden voltages plus the transmitter minimum operating voltage (typically 12-15V). For a 24V supply with a 250Ω burden (5V at 20 mA) and 2V wire drop, the transmitter has 17V available, which is adequate for most two-wire transmitters.
Symbols and units
| Symbol | Meaning | Default unit | Accepted units |
|---|---|---|---|
| V | Burden Voltage | V | pV, nV, µV, mV, V, kV |
| I | Loop Current | mA | pA, nA, µA, mA, A, kA |
| R | Burden Resistance | Ω | mΩ, Ω, kΩ, MΩ |
Step by step
- 1. What you know: Loop Current 20 mA, Burden Resistance 0.47 kΩ
- 2. The relation: V_burden = I_loop × R_burden
- 3. Substitute: I = 20 mA, R = 0.47 kΩ
- 4. Result: Burden Voltage = 9.4 V
Related quantities from the same inputs
- P = V × I = 0.188 W
Worked examples
Minimum range
Given: Loop Current 100 µA, Burden Resistance 1 Ω
Result: Burden Voltage = 100 µV
Low range
Given: Loop Current 1 mA, Burden Resistance 10 Ω
Result: Burden Voltage = 10 mV
Typical
Given: Loop Current 20 mA, Burden Resistance 0.47 kΩ
Result: Burden Voltage = 9.4 V
High range
Given: Loop Current 0.5 A, Burden Resistance 4.7 kΩ
Result: Burden Voltage = 2.35 kV
Maximum range
Given: Loop Current 5 A, Burden Resistance 47 kΩ
Result: Burden Voltage = 235 kV
Solving for each variable
Solve for Burden Voltage
Loop Current 100 µA, Burden Resistance 1 Ω → 100 µV
Solve for Loop Current
Burden Voltage 0.33 V, Burden Resistance 1 Ω → 0.33 A
Solve for Burden Resistance
Burden Voltage 0.33 V, Loop Current 100 µA → 3.3 kΩ
How Burden Voltage changes with Loop Current
| Loop Current (input) | Burden Voltage (result) |
|---|---|
| 2 mA | 0.94 V |
| 5 mA | 2.35 V |
| 10 mA | 4.7 V |
| 15 mA | 7.05 V |
| 20 mA | 9.4 V |
| 30 mA | 14.1 V |
| 40 mA | 18.8 V |
| 80 mA | 37.6 V |
| 140 mA | 65.8 V |
| 0.2 A | 94 V |
The same result in other units
| Unit | Value |
|---|---|
| µV | 9400000 |
| mV | 9400 |
| V | 9.4 |
| kV | 0.0094 |
Embed this calculator
Paste this into any page. It keeps working when this page updates, and credits the source.
<iframe src="https://vbatpower.com/embed/four-twenty-ma-burden/" width="100%" height="460" style="border:1px solid #1f2a37;border-radius:12px" loading="lazy" title="4–20 mA Burden Voltage"></iframe>
<p><a href="https://vbatpower.com/formulas/four-twenty-ma-burden/">4–20 mA Burden Voltage</a> Calculator by vbatpower.com</p>Frequently asked questions
How do you calculate 4–20 mA Burden Voltage?
Use V_burden = I_loop × R_burden. With Loop Current 20 mA, Burden Resistance 0.47 kΩ, Burden Voltage works out to 9.4 V.
What is the formula for 4–20 mA Burden Voltage?
The formula is V_burden = I_loop × R_burden. In a 4-20 mA current loop, the receiving device (PLC, DCS, or indicator) converts the current signal to a voltage by passing it through a precision burden resistor.
How do you find Loop Current when you know the other values?
Rearrange for Loop Current: with Burden Voltage 0.33 V, Burden Resistance 1 Ω, Loop Current is 0.33 A.
How do you find Burden Resistance when you know the other values?
Rearrange for Burden Resistance: with Burden Voltage 0.33 V, Loop Current 100 µA, Burden Resistance is 3.3 kΩ.
What units does 4–20 mA Burden Voltage use?
Burden Voltage is shown in µV, mV, V, kV. Values are held in SI base units internally, so you can mix prefixes without converting by hand.
Related Concepts
All Industrial / Process formulas →Need more features?
Save calculations, import telemetry data, simulate battery discharge, and collaborate with your team.
Try the App