Multiply a value: multiply

The multiply filter converts a value to a float and multiplies it by a specified amount. If the value cannot be converted to a number, it returns the default you provide instead of raising an error.

This is a convenient shorthand for scaling sensorSensors return information about a thing, for instance the level of water in a tank. [Learn more] values. Instead of converting to a float first and then multiplying, you can do it in a single step. Common uses include converting units (watts to kilowatts, Celsius to Fahrenheit), applying a cost rate to an energy reading, or scaling a percentage to a different range. For addition, see add.

Usage

Here’s how to use this template function. Copy any example and adjust it to your setup.

{{ states("sensor.power_watts") | multiply(0.001) }}

1.5

Function signature

The signature is a technical summary of this template function. It shows the name of the function, the values (called parameters) it accepts, and what type of data each parameter expects (for example, a piece of text or a number).

Function parameters that have a = with a value after them are optional. If you leave them out, the default value shown is used automatically. Function parameters without a default are required.

multiply(
    value: Any,
    amount: float,
    default: Any = _SENTINEL,
) -> float | Any

Function parameters

The following parameters can be provided to this filter.

Using a default value

If the sensor might be unavailable, provide a default to prevent errors.

{{ states("sensor.power_watts") | multiply(0.001, default=0) }}

1.5

Good to know

• There is no division filter. Pass a fractional amount, like 0.001 to divide by 1000.
• The result is always a float, even when both inputs are integers.
• Without a default, non-numeric input raises an error. Always pass a default when working with state values.

Try it yourself

Ready to test this? Open Developer tools > Template, paste the example into the Template editor, and watch the result update on the right. Edit the values to see how the function adapts to your own entitiesAn entity represents a sensor, actor, or function in Home Assistant. Entities are used to monitor physical properties or to control other entities. An entity is usually part of a device or a service. [Learn more].

More examples

Real scenarios where this function comes up in automations and templates. Copy any example and adapt it to your setup.

Convert watts to kilowatts

Scale a power reading from watts to kilowatts for cleaner display.

{{ states("sensor.power_usage") | multiply(0.001) | round(2) }}

1.50

Calculate energy cost

Multiply today’s energy consumption by the price per kWh.

{{ states("sensor.energy_today") | multiply(0.25) | round(2) }}

3.47

Scale a percentage to a brightness value

Convert a 0-100 percentage to a 0-255 brightness scale for a light.

action:
  - action: light.turn_on
    target:
      entity_id: light.desk_lamp
    data:
      brightness: >
        {{ states("sensor.ambient_light_pct") | multiply(2.55) | int(128) }}

Still stuck?

The Home Assistant community is quick to help: join Discord for real-time chat, post on the community forum with your template and expected result, or share on our subreddit /r/homeassistant.

Related template functions

These functions work well alongside this one:

• Add to a value: add - Adds a specified amount to a numeric value, with an optional default if conversion fails.

• Convert to float: float - Converts a value to a floating-point number, with an optional default if conversion fails.

• Convert to integer: int - Converts a value to an integer, with an optional default if conversion fails.

• Round a number: round - Rounds a numeric value to a specified number of decimal places using various rounding methods.