Signal-to-Noise Ratio Calculator
Calculate signal-to-noise ratios and power levels
Signal-to-noise ratio (SNR) is calculated using these formulas:
- Linear scale:
- SNR = Signal Power ÷ Noise Power
- Decibel scale:
- SNR (dB) = 10 × log₁₀(Signal Power ÷ Noise Power)
- Power in dBm:
- dBm = 10 × log₁₀(Power in watts ÷ 0.001)
This calculator handles all necessary conversions between linear and logarithmic scales automatically.
Common Units:
- Power: Measured in watts (W) or milliwatts (mW)
- SNR: Expressed as a ratio (linear) or in decibels (dB)
- Power Level: Often expressed in dBm (decibels relative to 1 milliwatt)
Key Conversions:
- 1 watt = 1000 milliwatts
- 0 dBm = 1 milliwatt
- 30 dBm = 1 watt
- Each 3 dB increase represents approximately doubling of power ratio
Signal-to-noise ratio calculations are essential for:
- Communications systems design
- Audio equipment evaluation
- Radio frequency systems
- Digital signal processing
- Image and video quality assessment
- Sensor system design
What is a good signal-to-noise ratio?
A good SNR depends on the application. For digital communications, an SNR above 20 dB is typically considered good. For audio systems, an SNR above 60 dB is desirable. Higher values indicate better signal quality relative to noise.
Why use decibels for SNR?
Decibels (dB) are used because they can represent very large or small ratios in a manageable scale, and they make multiplication and division operations into simple addition and subtraction. They're also logarithmic, which better matches human perception of sound and signal strength.
How can I improve signal-to-noise ratio?
SNR can be improved by either increasing signal power or reducing noise. Common methods include using better shielding, improving signal amplification, implementing noise reduction techniques, using better quality components, and optimizing system design.