Electrochemical Driving Force Calculator
For cations: +VDF = out (efflux), −VDF = in (influx); for anions: +VDF = in, −VDF = out. 0 = no net movement.
What Is Electrochemical Driving Force?
The electrochemical driving force (VDF) determines the net movement of ions across a membrane by comparing the membrane potential (Vm) and the ion's equilibrium potential (Veq). This concept is essential for understanding passive ion transport, neural signaling, and cellular electrochemical gradients.
The driving force is calculated using the formula:
VDF = Vm − Veq
How to Use the Electrochemical Driving Force Calculator
This calculator allows you to calculate any one of the three variables—membrane potential (Vm), equilibrium potential (Veq), or electrochemical driving force (VDF)—by leaving that field blank. Simply enter the other two and the calculator will compute the third.
You can choose units in either millivolts (mV) or volts (V). All values are internally converted to volts for accurate calculations. Once calculated, the tool also indicates the direction of ion movement based on the charge of the ion (cation or anion).
Ion Movement Interpretation
- Cations — Positive VDF: efflux (out), Negative VDF: influx (in)
- Anions — Positive VDF: influx (in), Negative VDF: efflux (out)
- Zero VDF — No net movement (equilibrium)
Features of This Tool
- Solves for Vm, Veq, or VDF automatically
- Supports both voltage units: mV and V
- Handles both cations and anions
- Shows real-time calculation and movement direction
- Displays full formula for clarity
This calculator is ideal for neuroscience, cell biology, physiology, or biophysics students and researchers needing to understand ion dynamics in membrane systems.