Volts To Millivolts
Convert Volts to Millivolts instantly for datasheets, meter readings and practical electronics work.
Last updated: May 2026
Enter a value to see the conversion instantly.
Why voltage-to-millivolt conversion matters
Sensor outputs, power supply ripple, and logic level thresholds are often specified at different scales. A temperature sensor might output 100 millivolts per degree, while a microcontroller expects its supply at 3.3 volts. A current-sense amplifier outputs millivolts that need converting to volts for the ADC input. This page handles those translations instantly. For the current example, 1 Volt equals 1000 Millivolts.
The formula is millivolts = volts × 1000. In practice, this matters when checking whether sensor outputs fit your circuit's input range, or when verifying that a power supply delivers the correct voltage under load.
Typical use cases
- Checking sensor output ranges (millivolts) against ADC input requirements (volts)
- Verifying power supply outputs match design specifications
- Translating between logic level standards (3.3V CMOS vs 5V TTL compatibility)
- Calculating gain needed for sensor amplification circuits
A practical example is confirming that a temperature sensor outputting 50 mV per °C will reach your microcontroller's full-scale ADC input of 3.3V without clipping, which requires checking the sensor's maximum output and the amplifier's gain in the same unit scale.
Quick reference
| Volts | Millivolts |
|---|---|
| 1 | 1000 |
| 1 | 1000 |
| 10 | 10000 |
| 100 | 100000 |
| 1000 | 1000000 |
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Frequently Asked Questions
Why do sensors output millivolts instead of volts?
Many sensors produce small signals—a thermocouple generates 40 µV/°C, a pressure transducer might output 5 mV at full scale, a current-sense resistor drops millivolts under load. Millivolts are the natural scale for these outputs. You must then amplify or directly read them depending on your circuit's input requirements (microcontroller ADC, op-amp stage, etc.). Converting to volts helps you check whether the sensor range matches your amplifier's gain or input range.
When do logic level differences matter in circuits?
3.3V microcontrollers (STM32, ESP32) cannot interpret 5V logic signals safely—they risk latch-up or damage. Conversely, 5V circuits may not recognize 3.3V as a reliable high logic state. Converting both supplies to millivolts (3300 mV vs 5000 mV) makes the incompatibility obvious and helps you design level shifters or choose compatible components. A simple rule: if the low-to-high threshold differs by more than a few hundred millivolts, you need translation circuitry.
How do I know if a power supply output is correct?
Power supplies are rated at nominal voltage with a tolerance band (e.g., 3.3V ±5% = 3.135V to 3.465V). Datasheets specify both the main output voltage and ripple in millivolts. A 3.3V supply might tolerate ±165 mV ripple. Converting your measured voltage to millivolts (e.g., 3.42V = 3420 mV) lets you check whether it falls within the tolerance and whether ripple stays below the limit for sensitive circuits like ADCs or phase-locked loops.
Can I amplify millivolt signals directly?
Yes, but you must know the exact millivolt range. A sensor outputting 0–100 mV (0.0–0.1 V) needs an amplifier with appropriate gain and input stage. If your ADC is 0–3300 mV full-scale, you need 33× gain to match 0–100 mV input to 0–3300 mV output. Without converting between millivolts and volts, the gain calculation becomes a unit mismatch—easier to work in millivolts throughout.
Why do batteries have different output voltages?
Battery voltage depends on chemistry. Alkaline (AA, AAA) output 1.5V, lithium cells 3V, lead-acid 2V per cell (12V for six cells), and LiPo 3.7V nominal. A circuit designed for 5V (e.g., four alkaline cells in series = 6V raw, regulated to 5V) fails if you substitute two lithium cells (6V unregulated). Converting to millivolts (1500 mV, 3000 mV, 3700 mV) makes voltage incompatibilities obvious when planning power supplies or replacements.