A **gear ratio calculator** is a **powerful tool** used to determine the **relationship** between two gears in a mechanical system.

The **gear reduction calculator** can perform several types of **conversions**, such as:

**Teeth count to ratio**: If you know the number of**teeth**on two meshing gears, the calculator can determine their**ratio**.**Diameter to ratio**: Using the**diameters**of two gears, it can calculate their**ratio**.**Ratio to RPM**: Given a gear**ratio**and the**RPM**of one gear, it can find the**RPM**of the other gear.

For example, if a **driving gear** has 20 teeth and a **driven gear** has 60 teeth, the gear ratio calculator would determine a **ratio** of 1:3, meaning the driven gear rotates **once** for every **three rotations** of the driving gear.

## Gear Ratio Calculator

Method | Driving Gear | Driven Gear | Calculation | Gear Ratio |
---|---|---|---|---|

Teeth Count | 20 teeth | 60 teeth | 60 / 20 | 3:1 |

Gear Diameter | 3 inches | 9 inches | 9 / 3 | 3:1 |

Pitch Diameter | 2.5 inches | 7.5 inches | 7.5 / 2.5 | 3:1 |

RPM | 3000 RPM | 1000 RPM | 3000 / 1000 | 3:1 |

**Conversion equation**: `Gear Ratio = Driven Gear Characteristic / Driving Gear Characteristic`

**Related Tools**

## Gear Ratio Formula

**Using Teeth Count**:`Gear Ratio = Number of Teeth on Driven Gear / Number of Teeth on Driving Gear`

**Using Gear Diameters**:`Gear Ratio = Diameter of Driven Gear / Diameter of Driving Gear`

**Using Pitch Diameters**:`Gear Ratio = Pitch Diameter of Driven Gear / Pitch Diameter of Driving Gear`

**Example**: If a driving gear has 25 teeth and a driven gear has 75 teeth, the gear ratio would be:

```
Gear Ratio = 75 / 25 = 3
```

This means the driven gear turns **once** for every **three rotations** of the driving gear.

## What is Gear Ratio?

**Gear ratio** is a **measure** of the **speed relationship** between two gears. It represents how many times one gear must rotate for the other gear to complete one **full rotation**.

Gear ratios are **crucial** in **mechanical engineering** as they allow for the modification of **torque**, **speed**, and **direction** of motion in machinery.

Key points about gear ratios:

- A
**ratio**greater than 1:1 indicates**speed reduction**and**torque increase**. - A
**ratio**less than 1:1 indicates**speed increase**and**torque reduction**. - Gear ratios are often expressed as a number followed by a colon and 1 (e.g., 3:1) or as a
**decimal**(e.g., 3.0).

Gear ratios play a **vital role** in various applications, from simple machines to complex **automotive transmissions**, allowing engineers to optimize **power delivery** and **efficiency** in mechanical systems.

## How to compute gear ratio?

Computing gear ratio involves following these **steps**:

**Identify the driving and driven gears**: The**driving gear**is the one that receives**power**, while the**driven gear**is the one that transmits that**power**.**Choose a method**: Decide whether you’ll use**teeth count**,**gear diameter**, or**pitch diameter**to calculate the**ratio**.**Measure or count**: Depending on your chosen method, either count the**teeth**or measure the**diameters**of both gears.**Apply the formula**: Use the appropriate**formula**from the ones mentioned earlier.**Simplify the ratio**: If necessary, reduce the**fraction**to its simplest form.

**Example**: Let’s say we have a driving gear with a diameter of 2 inches and a driven gear with a diameter of 6 inches.

Using the gear diameter formula:

```
Gear Ratio = 6 inches / 2 inches = 3:1
```

## How to combine gear ratios?

When dealing with multiple gear pairs in a system, you need to combine their **ratios** to get the overall **gear ratio**. To do this:

- Calculate the
**individual gear ratios**for each pair. **Multiply**these ratios together.

**Example**: In a **gearbox** with three gear pairs with ratios 2:1, 3:1, and 4:1, the combined ratio would be:

```
Combined Ratio = 2 × 3 × 4 = 24:1
```

## How to find gear ratio with RPM?

To find the gear ratio using **RPM** (Revolutions Per Minute), you can use this formula:

```
Gear Ratio = RPM of Driving Gear / RPM of Driven Gear
```

**Example**: If the driving gear rotates at 3000 RPM and the driven gear rotates at 1000 RPM, the gear ratio would be:

```
Gear Ratio = 3000 / 1000 = 3:1
```