Estimate performance from signal and noise data. Switch methods, inspect charts, and download result summaries. Built for testing, analysis, reporting, and practical comparison tasks.
| Case | Method | Signal | Noise | Impedance | Linear SNR | SNR dB |
|---|---|---|---|---|---|---|
| Audio amplifier | Power | 5 mW | 0.5 mW | Not required | 10 | 10.00 |
| Wireless receiver | Power | 2 W | 10 mW | Not required | 200 | 23.01 |
| Sensor output | Voltage | 2 V | 0.2 V | 50 Ω | 100 | 20.00 |
| Lab instrument | Voltage | 500 mV | 5 mV | 75 Ω | 10000 | 40.00 |
For power inputs, the linear signal to noise ratio is: SNR = Signal Power / Noise Power.
The decibel form is: SNR(dB) = 10 × log10(Signal Power / Noise Power).
For voltage inputs measured across the same impedance, the ratio becomes: SNR = (Signal Voltage / Noise Voltage)2.
The decibel form for equal-impedance voltages is: SNR(dB) = 20 × log10(Signal Voltage / Noise Voltage).
Signal to noise ratio shows how strong a useful signal is compared with unwanted noise. A higher value usually means clearer communication, better measurement quality, and more reliable interpretation.
Engineers, analysts, and technicians use SNR in audio systems, wireless links, sensors, medical instruments, cameras, and laboratory testing. Linear ratio helps direct comparison, while decibels make wide ranges easier to read.
This calculator supports both power-based and voltage-based workflows. Power mode works well for transmitters, receivers, and direct watt measurements. Voltage mode is useful when you have amplitudes from meters or oscilloscopes and a shared impedance.
The result section also estimates noise as a percentage of signal power and provides a simple quality label. That extra context can help when comparing designs, test conditions, or equipment settings.
SNR measures the strength of a useful signal compared with background noise. Higher values usually indicate cleaner data, stronger transmission quality, and easier interpretation of measured information.
Decibels compress large ranges into smaller numbers. That makes comparison easier, especially when signal and noise values differ by tens, hundreds, or thousands of times.
Choose power mode when your measurements are already expressed as watts, milliwatts, or similar power units. It directly applies the standard power ratio formula.
Choose voltage mode when you have signal and noise amplitudes measured across the same impedance. The calculator squares the voltage ratio to obtain the equivalent power ratio.
Yes. Voltage mode assumes signal and noise are measured across an equal impedance. That allows voltage values to be translated into comparable power values.
It depends on the application. Around 20 dB is often usable, while 40 dB or more is generally considered very strong for many measurement and communication tasks.
Yes. The calculator converts supported units into base values before computing the ratio. That lets you mix entries such as watts and milliwatts or volts and millivolts safely.
A low SNR usually means the noise level is too close to the signal level. Reducing interference, filtering noise, or increasing signal strength can improve it.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.