Op-Amp Calculators: Free Gain, Filter & Comparator Design Tools

Design precision analog circuits with our free online op-amp calculators. Whether you are calculating closed-loop gain for an inverting amplifier, determining component values for an active Butterworth filter, or sizing input resistors for a differential instrumentation amplifier, these tools deliver accurate results instantly. Enter your desired gain, bandwidth, supply voltage, and input signal range to receive resistor values, feedback capacitor sizes, slew rate requirements, and stability margins. Each calculator includes offset voltage compensation, common-mode rejection ratio effects, gain-bandwidth product limitations, and noise figure estimates for real-world performance. Students, audio engineers, and instrumentation designers use these tools to eliminate manual feedback network calculations and ensure stable, linear amplifier operation. From simple voltage followers to multi-pole active filters, our op-amp calculators cover every analog signal processing need. No signup required—access from any device and build precision analog circuits with confidence.