Rontoampere is 1e-27 ampere units.
Rontoamperes to Milliamperes Converter — rA to mA
Convert Rontoampere (rA) to Milliampere (mA) using the exact conversion factor (1 rontoampere = 1e-24 milliampere). See the formula, worked examples, and conversion table.
Rontoamperes to Milliamperes converter
Converter
Electricity Converter
Convert electrical units by family and calculate voltage, current, resistance, power, and energy with context values.
Context values
Some unit families need one extra value for a physically accurate result.
Milliampere is 0.001 ampere units.
Result = input x 1e-27 / 0.001.
Electrical units in the same family convert directly.
Reserved above the conversion cards and below the converter.
About Converting Rontoamperes to Milliamperes
Rontoampere and Milliampere both belong to the electricity family — voltage, current, resistance, power, or energy — units that show up constantly when working across the different standards used by household wiring (120V/240V depending on region), automotive electrical systems (12V/24V), and electronics design. Specifically: Rontoampere is 1e-27 ampere units, and milliampere is 0.001 ampere units.
Formula
milliamperes = rontoamperes × 1e-24
This factor comes from each unit's defined relationship to the category's base unit: 1 rontoampere equals 1e-27 base units, and 1 milliampere equals 0.001 base units, so dividing one by the other gives the direct rontoampere-to-milliampere factor of 1e-24.
Simple example
1 rA × 1e-24 = 1e-24 mA
1 rontoampere = 1e-24 milliamperes.
Real-world example
120 rA × 1e-24 = 1.2e-22 mA
120 rontoamperes = 1.2e-22 milliamperes.
Conversion table
| Rontoampere (rA) | Milliampere (mA) |
|---|---|
| 1 rA | 1e-24 mA |
| 5 rA | 5e-24 mA |
| 12 rA | 1.2e-23 mA |
| 24 rA | 2.4e-23 mA |
| 120 rA | 1.2e-22 mA |
| 240 rA | 2.4e-22 mA |
Reverse conversion: Milliampere to Rontoampere
1e-24 mA × 1e+24 = 1 rA
1e-24 milliamperes = 1 rontoamperes.
rontoamperes = milliamperes × 1e+24
For a page dedicated to this direction, see Milliampere to Rontoampere.
Understanding the Rontoampere (rA)
Rontoampere is 1e-27 ampere units.
Understanding the Milliampere (mA)
Milliampere is 0.001 ampere units.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many milliamperes are in 1 rontoampere?
1 rontoampere equals 1e-24 milliamperes, using the exact defined conversion factor rather than an estimate.
How do I convert rontoampere to milliampere?
Multiply the rontoampere value by 1e-24. The converter above does this instantly to whatever precision you set.
How do I convert milliampere back to rontoampere?
Use the reverse factor: 1 milliampere equals 1e+24 rontoamperes. You can also use the swap control in the converter above to flip the direction instantly.
What is a rontoampere?
Rontoampere (rA) is a unit of electricity.
What is a milliampere?
Milliampere (mA) is a unit of electricity.
Is the rontoampere to milliampere conversion exact?
Yes. Both rontoampere and milliampere are defined by fixed standards rather than physical artifacts, so the factor of 1e-24 used above is exact to as many digits as you choose to display.
What's the difference between voltage, current, and resistance?
Voltage (volts) is the electrical potential difference driving current through a circuit. Current (amperes) is the rate of flow of electric charge. Resistance (ohms) is how much a component opposes that flow. They're related by Ohm's law (V = I × R), but they are distinct physical quantities, and this page converts between units of just one of them.