Inverting Op-Amp Resistor Calculator

Inverting Op AMP Resistor Calculator is a great op amp calculation tool for the operational amplifier inverting circuit. With this inverting amplifier calculator, you are able to calculate the resistance of R2, R3 and R4 resistor with ease. Because you just enter the input parameters of inverting op amp gain, the output voltage(Vout), R1 Resistance, the values of V1, V2, Vp and Vn, and then click the "Calculate" button.

Input Parameters (Inverting Op-amp)
VoutV
Gain
R1KOhms
V1(Input lead)V
V2 (non-zero only if offset is requred)V
VpV
VnV
Outputs
R2KOhms
R3KOhms
R4KOhms
Op-Amp Circuit Schematic
Introduction

Easy to follow and comprehensive video of the circuit operation and design of a inverting op amp circuit: operational amplifier circuit gain; resistor value calculation, input impedance, power supplies . . . all you need to know.  In this video we look at the inverting operational amplifier circuit. Description of how the circuit works is provided along with details of the components needed.  The advantages and disadvantages of the inverting op amp circuit are discussed: its input impedance, output impedance and mention is made of the virtual earth point in the circuit.  The formula of equation for gain is given along with a worked example of calculating the non-inverting circuit gain.  Circuits are given for the inverting operational amplifier using positive and negative supplies, i.e. differential supplies as well as from a single ended supply, i.e. a single supply against ground.   Finally some useful practical hints and tips are given gained from practical experience as a design engineer.

Op Amp Inverting Amplifier Circuit Design | Operational Amplifier Circuit

OP AMP Resistor Calculator Overview

OP AMP Resistor Calculator is designed by Utmel Electronic, which is one of the most professional Electrical components distributors in the World. And this calculation tool is used for inverting operational amplifier to calculates the output values of the resistors R2, R3 and R4 in the inverting OP-AMP circuit. And the output properties are in KΩohms (kilo-ohms). And you should know the parameters of operational amplifier gain, R1(KΩohms), Vout, Vp, V2 and Vn before do the operational amplifier calculation.

Definition of Inverting Op Amp

The op amp inverting amplifier circuit is simple to build and construct, requiring only a few basic electrical components. An operational amplifier circuit having an output voltage that varies in the opposite direction as the input voltage is called an inverting op amp. In other terms, it is 180 degrees out of phase.

Inverting vs. Non inverting op amp

inverting-noninverting-opamp.png

Inverting OP AMP Amplifier

inverting-operational-amplifier-circuit.png

The operational amplifier's inverting input gets feedback from the amplifier's output in an inverting amplifier circuit. The voltage at the inverting terminal is identical to the voltage at the non-inverting terminal if the op-amp is perfect and the notion of virtual short is applied at the input terminals of the op-amp. The operational amplifier's non-inverting input is linked to ground. The difference between the two input terminals is extremely minor and may be ignored because the gain of the op amp is quite high and the output from the amplifier is only a few volts. Because the operational amplifier's non-inverting input is maintained at ground potential, the inverting input must also be held at ground potential.

Non-Inverting OP Amp Amplifier

The output of a non-inverting amplifier is in phase with the input. The inverting input is where the feedback is applied. The input, on the other hand, is now applied to the non-inverting input. The output is an amplified version of the input that is not inverted (in terms of phase). The gain of the operational amplifier's non-inverting amplifier circuit is simple to calculate. The computation is based on the assumption that both inputs have the same voltage. The reason for this is that the amplifier's gain is quite high. If the circuit's output remains inside the amplifier's supply rails, the output voltage divided by the gain indicates that there is almost no difference between the two inputs.

More Resistor Calculators

LED Series Resistor Calculator -  to calculate the resistance of the resistor in a LED series.

Resistor Color Code Calculator - to find the tolerance and resistance values for  through hole resistors with 4, 5 and 6 band color codes.

SMD Resistor Code Calculator - to determine the value of any SMD resistor with 3 or 4 digit code.

Parallel and Series Resistor Calculator - to find the total equivalent resistance of a series or parallel resistance circuit.

Frequently Asked Questions

What input parameters are required for calculating R2, R3, and R4?

You need to input the desired gain (negative value), R1 resistance (in kΩ), output voltage (Vout), power supply voltages (Vp and Vn), and optional offset voltage V2.

How are R2, R3, and R4 calculated in the inverting amplifier circuit?

R2 is derived from the gain formula: R2 = |Gain| × R1. R3 and R4 (optional bias resistors) balance input bias currents. If no offset is required (V2 = 0), R3 and R4 are typically omitted or set to match R1||R2.

Why might my calculated Vout exceed the allowed range?

The output voltage Vout must stay within the op-amp’s supply rails (Vn ≤ Vout ≤ Vp). If your input gain or R1/R2 ratio forces Vout beyond these limits, the result will be invalid (clipped). Adjust your parameters accordingly.

What is the purpose of R3 and R4 in the circuit?

R3 and R4 (if used) minimize errors from input bias currents. They are often set to R3 = R4 = R1 || R2 (parallel combination of R1 and R2) to balance the input impedance. If no offset is needed, these resistors can be omitted.

Can this calculator handle non-inverting or differential amplifier designs?

No, this tool is specific to inverting op-amp circuits. For non-inverting, differential, or other configurations, use a dedicated calculator tailored to those topologies.
Hot products

ImagePart NumberManufacturerCategoryPackage/CaseDescriptionPriceQuantityBuy/Quote
MMBT2222ALT1GMMBT2222ALT1GON SemiconductorTransistors - Bipolar (BJT) - SingleTO-236-3, SC-59, SOT-23-3TRANS NPN 40V 0.6A SOT23-

In stock : 682665

Minimum: 1

ATMEGA8515L-8AUATMEGA8515L-8AUMicrochip TechnologyEmbedded - Microcontrollers44-TQFPMCU 8-bit ATmega AVR RISC 8KB Flash 3.3V/5V 44-Pin TQFP-

In stock : 1

Minimum: 1

STM32F103RBT6STM32F103RBT6STMicroelectronicsEmbedded - Microcontrollers64-LQFPIC MCU 32BIT 128KB FLASH 64LQFP-

In stock : 7681

Minimum: 1

ATMEGA32A-AUATMEGA32A-AUMicrochip TechnologyEmbedded - Microcontrollers44-TQFPMCU 8-Bit ATmega AVR RISC 32KB Flash 3.3V/5V 44-Pin TQFP-

In stock : 16000

Minimum: 1

ATXMEGA128A1U-AUATXMEGA128A1U-AUMicrochip TechnologyEmbedded - Microcontrollers100-TQFPIC MCU 16BIT 128KB FLASH 100TQFP-

In stock : 1480

Minimum: 1

STM32F407VET6STM32F407VET6STMicroelectronicsEmbedded - Microcontrollers100-LQFPMCU 32-bit STM32F ARM Cortex M4F RISC 512KB Flash 2.5V/3.3V 100-Pin LQFP Tray-

In stock : 6280

Minimum: 1

STM32F405RGT6STM32F405RGT6STMicroelectronicsEmbedded - Microcontrollers64-LQFPMCU 32-bit STM32F ARM Cortex M4F RISC 1024KB Flash 2.5V/3.3V 64-Pin LQFP Tray-

In stock : 28349

Minimum: 1

STM32F103VBT6STM32F103VBT6STMicroelectronicsEmbedded - Microcontrollers100-LQFPMCU 32-bit STM32F1 ARM Cortex M3 RISC 128KB Flash 2.5V/3.3V 100-Pin LQFP Tray-

In stock : 4951

Minimum: 1

PIC18F46K20-I/PTPIC18F46K20-I/PTMicrochip TechnologyEmbedded - Microcontrollers44-TQFPIC MCU 8BIT 64KB FLASH 44TQFP-

In stock

Minimum: 1

STM8S003F3U6TRSTM8S003F3U6TRSTMicroelectronicsEmbedded - Microcontrollers20-UFQFNSTMICROELECTRONICS - STM8S003F3U6TR - MCU-

In stock : 150000

Minimum: 1

PIC16F883-I/SSPIC16F883-I/SSMicrochip TechnologyEmbedded - Microcontrollers28-SSOP (0.209, 5.30mm Width)8-bit Microcontrollers - MCU 7KB Flash 256 RAM 25 I/O-

In stock : 282

Minimum: 1

IRLR7843TRPBFIRLR7843TRPBFInfineon TechnologiesTransistors - FETs, MOSFETs - SingleTO-252-3, DPak (2 Leads + Tab), SC-63MOSFET N-CH 30V 161A DPAK-

In stock : 1124

Minimum: 1

STM32F427VIT6STM32F427VIT6STMicroelectronicsEmbedded - Microcontrollers100-LQFPARM Microcontrollers - MCU 32B ARM Cortex-M4 2Mb Flash 168MHz CPU-

In stock : 7506

Minimum: 1

NTA4153NT1GNTA4153NT1GON SemiconductorTransistors - FETs, MOSFETs - SingleSC-75, SOT-416MOSFET N-CH 20V 915MA SOT-416-

In stock : 382200

Minimum: 1

STM32F103RET6STM32F103RET6STMicroelectronicsEmbedded - Microcontrollers64-LQFPMCU 32-bit STM32F1 ARM Cortex M3 RISC 512KB Flash 2.5V/3.3V 64-Pin LQFP Tray-

In stock : 12380

Minimum: 1

PIC16F877-20I/PTPIC16F877-20I/PTMicrochip TechnologyEmbedded - Microcontrollers44-TQFPIC MCU 8BIT 14KB FLASH 44TQFP-

In stock : 3300

Minimum: 1

LAN8720A-CP-TRLAN8720A-CP-TRMicrochip TechnologyInterface - Drivers, Receivers, Transceivers24-VFQFN Exposed PadIC TXRX ETHERNET 24QFN-

In stock : 4970

Minimum: 1

RB521S30T1GRB521S30T1GON SemiconductorDiodes - Rectifiers - SingleSC-79, SOD-523DIODE SCHOTTKY 30V 200MA SOD523-

In stock : 120000

Minimum: 1

PIC18F4685-I/PTPIC18F4685-I/PTMicrochip TechnologyEmbedded - Microcontrollers44-TQFPIC MCU 8BIT 96KB FLASH 44TQFP-

In stock : 8

Minimum: 1

BLM18PG121SN1DBLM18PG121SN1DMurata ElectronicsFerrite Beads and Chips0603 (1608 Metric)MURATA - BLM18PG121SN1D - Ferrite Bead
  • 1:$0.174118
  • 10:$0.164262
  • 100:$0.154964
  • 500:$0.146193

In stock : 5540

Minimum: 1