> ## Documentation Index
> Fetch the complete documentation index at: https://docs.kalshi.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Subpenny Pricing

> Dollar-based pricing format for subpenny precision

For the general overview of fixed-point pricing and contract quantities across REST and WebSocket APIs, see [Fixed-Point Representation](/getting_started/fixed_point_migration.md).

## Technical Specification

To enable subpenny precision, include tag **21005** in your Logon message:

| Tag | Name | Description | Value |
| - | - | - | - |
| 21005 | UseDollars | Enable dollar-based price format | Y |

Overview:

* **Legacy Format (Cents)**: Used when `UseDollars(21005)` is omitted or `N`. Prices given in whole cents. E.g. 72 cents = `72`.
* **New Format (Dollars)**: Prices normalized to dollars with fixed precision (up to 4 decimal places).

> [!NOTE]
>
> In legacy cents mode, fractional `Price(44)` input is currently truncated when parsing the order. For example, `44=50.5` submits a 50-cent limit price. To submit 50.5 cents, set `21005=Y` at Logon and send `44=0.5050`.

Examples:

| Cents | FIX Decimal | String Representation |
| - | - | - |
| 1.23¢ | Decimal(123, -4) | 0.0123 |
| 72.5¢ | Decimal(7250, -4) | 0.725 |
| 99¢ | Decimal(9900, -4) | 0.99 |

Affected Tags:

| Tag | Field Name | Description |
| - | - | - |
| 6 | AvgPx | Average price of fills |
| 31 | LastPx | Price of last fill |
| 44 | Price | Order limit price |
| 132 | BidPx | Quote bid price |
| 133 | OfferPx | Quote ask price |

## Sample Messages

```FIX logon theme={null}
8=FIXT.1.1|9=300|35=A|34=1|52=20250926-21:54:07.001|
96=QhA8659Mhygcm+xE/wb1m...|21005=Y|
                            ^^ Enable dollar format
```

```FIX new order single theme={null}
8=FIXT.1.1|9=200|35=D|34=2|52=20250926-21:54:16.040|
38=100.0|40=2|44=0.7500|54=1|60=20250926-21:54:16.040|
              ^^ price
10=092|
```

```FIX execution report theme={null}
8=FIXT.1.1|9=400|35=8|34=4|52=20250926-21:54:16.159|
6=0.6600|14=100|31=0.7000|32=60|38=100.0000|39=2|44=0.7500|
^^ avgPx        ^^ lastPx                        ^^ price
```


This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.