The formula to convert Fahrenheit to Celsius is:

```

°C = (°F - 32) × 5/9

```

Where:

* °C is the temperature in Celsius

* °F is the temperature in Fahrenheit

So, to convert 10°F to Celsius, we would use the formula:

```

°C = (10 - 32) × 5/9

°C = (-22) × 5/9

°C = -12.22

```

Therefore, 10°F is equal to -12.22°C.