---
title: Odds format
updatedAt: 2025-03-31T15:10:42.000Z
---

Fetch the complete documentation index at: https://docs.watchers.io/llms.txt

# Odds format

The `oddsformat` GET parameter is available on the page where copy-betting is enabled. With this parameter, you can choose how the odds (coefficients) are displayed.

1. **`decimal`** — decimal format (the standard option)
2. **`american`** — American format (US odds)

If the parameter is not specified or an invalid value is passed, the default **`decimal`** format is used.

***

### 1. Decimal Format (`decimal`)

When `decimal` is selected, odds are displayed in a familiar decimal format, such as `1.4`, `3.0`, or `99.0`. By convention, no more than two decimal places are shown.

***

### 2. American Format (`american`)

When `american` is selected, decimal odds are automatically converted to American (US) odds using the following rules:

#### 2.1 Main Conversion Formula

* If the decimal odds **D \< 2**:
  ```
  USOdds = -1 * ceil(100 / (D - 1))
  ```
  where `ceil` denotes rounding up.

* If the decimal odds **D >= 2**:
  ```
  USOdds = floor(100 * (D - 1))
  ```
  where `floor` means truncating the decimal part.

#### 2.2 Special Case for |USOdds| > 1000

If the absolute value of the result exceeds 1000, the value is additionally rounded down to the nearest multiple of 5. Specifically:

* For positive values (when D ≥ 2), round down (e.g., 1142 → 1140).
* For negative values (when D \< 2), round in the "larger magnitude" direction, resulting in a more negative number (e.g., -1698 → -1700).

***

### Examples

1. **Decimal: 1.1112**
   ```
   USOdds = -1 * ceil(100 / (1.1112 - 1))
          = -1 * ceil(899.28057)
          = -900
   ```
   Final value: **-900** (no additional rounding needed).

2. **Decimal: 5.3334**
   ```
   USOdds = floor(100 * (5.3334 - 1))
          = floor(433.34)
          = 433
   ```
   Final value: **433**.

3. **Decimal: 1.0589**
   ```
   USOdds = -1 * ceil(100 / (1.0589 - 1))
          = -1 * ceil(1697.79)
          = -1698
   ```
   Since 1698 > 1000, it is rounded to the nearest multiple of 5: **-1700**.

4. **Decimal: 12.4286**
   ```
   USOdds = floor(100 * (12.4286 - 1))
          = floor(1142.86)
          = 1142
   ```
   Since 1142 > 1000, it is also rounded down to a multiple of 5: **1140**.

***

### Using the `oddsformat` Parameter

To apply this functionality, simply pass the `oddsformat` parameter in the URL:

* `oddsformat=decimal` → Odds are displayed in decimal format (1.4, 3.0, 99.0, etc.).
* `oddsformat=american` → Odds are displayed in American format (-900, +433, -1700, +1140, etc.).

If the parameter is omitted or an invalid value is passed, the **`decimal`** format is automatically used.

***

### Additional Details

* When odds exceed 1000 in absolute value, they are always rounded down to the nearest multiple of 5, which can sometimes slightly benefit the player.
* This feature is fully available in production and can be used to customize how odds are displayed in copy-betting widgets.