# Turbo Size Calculator

## Turbo Size Calculator

How do you determine the correct size for a turbocharger? Its easy, use our Turbo Size Calculator that can help you find the appropriate turbo size based on specific input values. Enter the **engine displacement**, **desired horsepower**, **boost pressure**, **volumetric efficiency**, and **RPM** into the calculator to find the turbo size you need.

### How to Use?

To use the Turbo Size Calculator is simple. Follow these steps:

**Enter the Engine Displacement**: Input the engine displacement in cubic inches (ci).- Example:
`350 ci`

- Example:
**Enter the Desired Horsepower**: Input the horsepower you aim to achieve.- Example:
`500 hp`

- Example:
**Enter the Boost Pressure**: Input the boost pressure in psi.- Example:
`15 psi`

- Example:
**Enter the Volumetric Efficiency**: Input the efficiency percentage. This is usually around 85%.- Example:
`85%`

- Example:
**Enter the RPM**: Input the engine’s revolutions per minute.- Example:
`6000 rpm`

- Example:

After entering these values, click the “Calculate” button to find the turbo size.

## What is Turbo Size?

Turbo size means how much a turbo boosts an engine. It is key to spiking engine power by cramming more air in the boom box. This lets the engine burn extra fuel and make extra force. A turbo jack ups air to hike power. Size counts for thrust gains.

### Formula

The formula to calculate the turbo size is:

$\text{TurboSize}=\frac{\text{AirFlowRate}\times \left(\frac{\text{VolumetricEfficiency}}{100}\right)\times \left(\frac{\text{RPM}}{3456}\right)}{6}$

Where the air flow rate is calculated as:

$\text{AirFlowRate}=\frac{\text{DesiredHorsepower}\times 1.45}{\text{BoostPressure}+14.7}$

Variables

Variable | Description |
---|---|

Engine Displacement (ci) | Volume of the engine in cubic inches |

Desired Horsepower (hp) | Target horsepower output |

Boost Pressure (psi) | Pressure of the turbo boost in psi |

Volumetric Efficiency (%) | Efficiency of the engine’s air intake |

RPM | Engine revolutions per minute |

Air Flow Rate (lb/min) | Rate at which air flows into the engine |

Turbo Size (lb/min) | Required size of the turbocharger |

## Calculation Examples

### Example 1

For example your input is:

**Input**:

**Engine Displacement (ci)**:`400`

**Desired Horsepower (hp)**:`600`

**Boost Pressure (psi)**:`20`

**Volumetric Efficiency (%)**:`90`

**RPM**:`7000`

**Calculation Steps**:

**1. Calculate the Air Flow Rate**:

$\text{Air Flow Rate}=\frac{600\times 1.45}{20+14.7}$

$=\frac{870}{34.7}$

$\approx 25.07\text{\hspace{0.17em}}\text{lb/min}$

**2. Calculate the Turbo Size**:

$\text{TurboSize}=\frac{25.07\times \left(\frac{90}{100}\right)\times \left(\frac{7000}{3456}\right)}{60}$

$=\frac{25.07\times 0.9\times 2.024}{60}$

$\frac{45.75}{60}$

$\approx 0.76\text{\hspace{0.17em}}\text{lb/min}$

Result: The required turbo size is approximately **0.76 lb/min**.

### Example 2

For example your input is:

**Input**:

**Engine Displacement (ci)**:`300`

**Desired Horsepower (hp)**:`450`

**Boost Pressure (psi)**:`10`

**Volumetric Efficiency (%)**:`85`

**RPM**:`6500`

**Calculation Steps**:

**1. Calculate the Air Flow Rate**:

$\text{AirFlowRate}=\frac{450\times 1.45}{10+14.7}$

$=\frac{652.5}{24.7}$

$\approx 26.42\text{\hspace{0.17em}}\text{lb/min}$

**2. Calculate the Turbo Size**:

$\text{TurboSize}=\frac{26.42\times \left(\frac{85}{100}\right)\times \left(\frac{6500}{3456}\right)}{60}$

$\frac{26.42\times 0.85\times 1.88}{60}$

$=\frac{42.34}{60}$

$\approx 0.71\text{\hspace{0.17em}}\text{lb/min}$

Result: The required turbo size is approximately **0.71 lb/min**.

I hope this turbo calc makes turbo size picks easy. Put in what’s known, it does the rest. Handles finding the right cram for your engine boom box just from few clear inputs. Makes turbo choice views quick.