Signal-to-Noise Ratio Calculator

Calculate SNR for electronics, communications, and signal processing applications

Calculate Signal-to-Noise Ratio

Choose the type of SNR calculation based on your signal measurements

W

Magnitude of the desired signal

W

Magnitude of the background noise

SNR Results

0.000 dB
Poor
Signal Quality
0.00 dB
SNR in Decibels
1.00
Linear Ratio
50.0%
Signal Strength
Connection Quality:Poor

Cannot establish reliable connection

Formula:

Input values: Signal: 0 W, Noise: 0 W

Example Calculation

Voltage SNR Example

Signal voltage: 6 V

Noise voltage: 4 V

SNR Type: Voltage SNR

Step-by-step Calculation

1. SNR = 20 × log₁₀(Signal / Noise)

2. SNR = 20 × log₁₀(6 / 4)

3. SNR = 20 × log₁₀(1.5)

4. SNR = 20 × 0.176 = 3.52 dB

Result: Good signal quality

SNR Quality Guidelines

Poor (< 10 dB)Unreliable
Fair (10-15 dB)Poor quality
Acceptable (15-25 dB)Usable
Good (25-40 dB)Good quality
Excellent (> 40 dB)Excellent

SNR Calculation Types

Power SNR

10 × log₁₀(P_signal / P_noise)

Voltage SNR

20 × log₁₀(V_signal / V_noise)

Decibel SNR

Signal(dB) - Noise(dB)

Linear Ratio

Signal / Noise

Coefficient

Mean / Standard Deviation

Common Applications

Wireless communication systems

Audio and video processing

Radar and sonar systems

Digital signal processing

Medical imaging systems

Understanding Signal-to-Noise Ratio

What is SNR?

Signal-to-Noise Ratio (SNR) is a measure that compares the level of a desired signal to the level of background noise. It's expressed as a ratio and typically measured in decibels (dB). A higher SNR indicates better signal quality with less interference from noise.

Why is SNR Important?

  • Determines communication system performance
  • Affects data transmission reliability
  • Influences audio and video quality
  • Critical for scientific measurements

SNR Calculation Methods

Power SNR: SNR = 10 × log₁₀(P_signal / P_noise)

Voltage SNR: SNR = 20 × log₁₀(V_signal / V_noise)

Decibel SNR: SNR = Signal(dB) - Noise(dB)

Linear Ratio: SNR = Signal / Noise

Coefficient: SNR = μ / σ

Interpretation Guidelines

  • Positive SNR: Signal stronger than noise
  • Zero SNR: Signal equals noise level
  • Negative SNR: Noise stronger than signal
  • Higher values: Better signal quality

Types of Noise

  • Thermal noise: Random motion of electrons
  • Electronic noise: Circuit component variations
  • Quantum noise: Fundamental physics limitations
  • Environmental noise: External interference
  • Acoustic noise: Sound interference

Practical Applications

  • WiFi networks: Minimum 20 dB for reliable internet
  • Voice calls: Minimum 25 dB for clear audio
  • Digital TV: Minimum 15 dB for acceptable quality
  • Scientific instruments: Often require > 40 dB
  • Audio equipment: 60+ dB for high fidelity