Electric Field Converter
Convert electric field strength between V/m, kV/m, N/C, V/cm, and statV/cm. Enter a value, then choose the From unit and To unit.
Convert Electric Field Strength Between Units
Electric Field Conversion Formula
Where:
- \(E_{\mathrm{from}}\) — the value entered in the From unit.
- \(E_{\mathrm{to}}\) — the converted value in the To unit.
- \(f_{\mathrm{from}}\) and \(f_{\mathrm{to}}\) — the calculator’s conversion factors relative to V/m.
The calculator multiplies by the factor for the starting unit and divides by the factor for the destination unit. Its statV/cm factor is incorrect; see the limitation below before using conversions involving that unit.
Electric Field Conversion – Calculation Example
Example: convert the default value of 1,000 V/m to kV/m. The calculator uses factors of 1 for V/m and 1,000 for kV/m.
\[E_{\mathrm{to}}=1{,}000\times\frac{1}{1{,}000}=1\ \mathrm{kV/m}\]
Result: 1,000 V/m = 1 kV/m.
How to use the calculator
- Enter the nonnegative strength you want to convert in Electric field value. Enter a number only; select its unit separately.
- Choose the value’s existing unit under From unit.
- Choose the desired unit under To unit.
- Read Converted Electric Field Strength. The result includes the selected destination unit and is rounded to six decimal places.
The available units are volts per meter (V/m), kilovolts per meter (kV/m), newtons per coulomb (N/C), volts per centimeter (V/cm), and statvolts per centimeter (statV/cm). If you choose the same unit in both menus, the numerical value stays the same, subject to the displayed rounding.
What electric field strength means
Electric field strength describes the force that an electric field would exert per unit of positive test charge at a point. Its SI unit is the newton per coulomb (N/C). It can also be expressed in volts per meter (V/m): 1 N/C is exactly 1 V/m. The two units describe the same quantity from force-per-charge and potential-gradient perspectives.
In a uniform field, such as the idealized field between parallel plates, field strength is the voltage difference divided by the separation in meters. For example, 100 V across a 0.01 m gap gives 10,000 V/m, or 10 kV/m. This simple relationship is useful for estimating a field, but an actual field may vary with position, especially near edges or irregularly shaped electrodes.
Changing units does not change the physical field. For instance, 1 V/cm equals 100 V/m, while 1 kV/m equals 1,000 V/m. Choosing a convenient unit makes it easier to compare measurements, specifications, or calculations without carrying unnecessarily large or small numbers. Electric fields are distinct from magnetic flux density, even though the two are often discussed together in electromagnetism.
Conversion factors and important limitations
The table shows how many V/m correspond to one unit. These factors are also the ones used by the calculator, except that its statV/cm factor differs from the physically correct conversion.
| Unit | V/m per unit | Calculator status |
|---|---|---|
| V/m | 1 | Correct |
| kV/m | 1,000 | Correct |
| N/C | 1 | Correct |
| V/cm | 100 | Correct |
| statV/cm | Approximately 29,979.2458 | Uses 299.792458 instead |
Do not rely on results involving statV/cm. One statvolt is approximately 299.792458 volts, but one centimeter is 0.01 meter. Therefore, 1 statV/cm is approximately 29,979.2458 V/m, not 299.792458 V/m. The calculator’s factor is 100 times too small: conversions from statV/cm to other units produce results 100 times too small, and conversions into statV/cm produce results 100 times too large. Conversions that use only V/m, kV/m, N/C, and V/cm are unaffected.
This tool converts field-strength units; it does not calculate a field from voltage, charge, or geometry. The input accepts nonnegative values only, so it cannot represent a signed field component or direction. Very small converted values may display as zero because results are rounded to six decimal places. Keep direction and measurement conditions separately when comparing fields. If your wider calculation involves moving charge or magnetic effects, the electric current converter and magnetic flux converter handle those different quantities.
Frequently Asked Questions
How can I convert electric field units by hand?
Convert the starting value to V/m, then convert that result to the target unit. For example, 25 V/cm is 2,500 V/m because each centimeter is 0.01 meter. Dividing by 1,000 gives 2.5 kV/m. For conversions involving statV/cm, use the physically correct factor rather than the calculator’s factor.
What is a normal or safe electric field strength?
There is no single normal or safe value: the answer depends on the setting, exposure conditions, and what you are assessing. For perspective, dry air can break down at roughly 3 million V/m under idealized conditions, but humidity, electrode shape, and spacing affect the actual threshold. That breakdown figure is not a human-exposure safety limit.
How do I correctly convert statV/cm?
Use approximately 29,979.2458 V/m for each statV/cm. Multiply a value in statV/cm by that number to obtain V/m; divide a value in V/m by it to obtain statV/cm. The calculator uses a factor 100 times too small, so do not use its results when either selected unit is statV/cm.
Can I compare an AC electric field reading with a DC field value?
Only if you know what each number represents. An AC reading may be reported as a peak value or a root-mean-square (RMS) value, while a DC value is typically constant. For a sinusoidal field, peak strength is approximately
How is electric field strength related to force on a charge?
The force on a charge is
Does a higher voltage always mean a stronger electric field?
No. Field strength also depends on how the voltage changes across space. The same voltage across a smaller gap generally produces a stronger field; electrode shape can concentrate the field locally as well. A voltage rating alone is therefore not enough to determine the field at a particular point.