A non-inverting amplifier is an op-amp circuit that boosts a signal while keeping it in phase — meaning the output voltage rises and falls in sync with the input. Enter your Input Voltage (Vin), Input Resistor (R1), and Feedback Resistor (R2) into the Non-Inverting Amplifier Calculator to find the Voltage Gain (Av). Secondary outputs include Output Voltage (Vout) and Gain in dB.
Voltage Gain (Av)
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Output Voltage (Vout)
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Gain in dB
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The voltage gain of a non-inverting op-amp is calculated using the formula: Gain = 1 + (Rf/Rin), where Rf is the feedback resistor and Rin is the input resistor. This formula shows that the minimum gain is 1 (unity gain) when Rf = 0.
In a non-inverting configuration, the output voltage has the same polarity as the input voltage, and the minimum gain is 1. In an inverting configuration, the output voltage is inverted (opposite polarity) relative to the input, and the gain formula is -Rf/Rin.
Choose resistor values based on your desired gain and input impedance requirements. Higher resistance values reduce current consumption but may increase noise. Typical values range from 1kΩ to 1MΩ. The ratio Rf/Rin determines the additional gain beyond unity.
A non-inverting op-amp has very high input impedance, theoretically infinite for an ideal op-amp. In practice, it's typically in the range of 10^12 ohms or higher, making it excellent for buffering high-impedance sources.
No, the gain of a non-inverting op-amp cannot be less than 1. The minimum gain is unity (1) when the feedback resistor Rf is zero or when there's a direct connection from output to the inverting input.
To convert voltage gain to decibels, use the formula: Gain (dB) = 20 × log10(Voltage Gain). For example, a voltage gain of 10 equals 20 dB, and a gain of 100 equals 40 dB.
Non-inverting op-amps are commonly used as voltage followers (unity gain buffers), signal amplifiers, impedance converters, and in instrumentation amplifiers where you need to amplify a signal without changing its polarity.