# llGetMass

*LSL function*

```lsl
float float llGetMass();
```

- Returns: `float`
- Energy: 10

Returns a float representing the mass of the object (in lindograms). Returns the total linkset mass if called from the root, or the individual prim's mass if called from a child prim. Returns the wearer's mass if inside an attachment.

Returns a [float](https://wiki.secondlife.com/wiki/float) that is the mass of object (in [lindograms](#lindograms)) that script is attached to.

```lsl title="How to use" frame="terminal"
float result = llGetMass();
```

## Caveats

- The mass reported by this function is in [lindograms](#lindograms), which function the same as kilograms within the bounds of Second Life, but not elsewhere. ([See below](#lindograms))
- Attachments do not affect an avatar's mass, only certain Appearance settings.
- Avatar mass is reported to either be unexpectedly low (when measured using [llGetMass](/functions/llGetMass/)) or unexpectedly high (when measured using [llGetMassMKS](/functions/llGetMassMKS/)). This is likely due to the weight being calculated based on a fixed value, with a modifier for height. The fixed value being used is incorrect, likely due to an incorrect density value being used.

## Examples

<details open>
<summary>Example 1</summary>

```lsl
//A way of making a constant force that returns the same speed visually whatever the object is
default
{
    touch_start()
    {
        llApplyImpulse(<0.0, 0.0, 5.0> * llGetMass(), FALSE);
        // This fires the object up at the same m/s whatever the size (or difference!)
    }
}//Written by El Taka
```

</details>

## Notes

"Lindograms" is the name of the primary unit of mass used in Second Life.

While Second Life primarily makes use of the [SI system of units](https://en.wikipedia.org/wiki/International_System_of_Units), mass seems to be an exception.

Some speculate that lindograms were intended to be *kilograms*, but a mistake was made when factoring object density, causing the mass value returned to be 100 times less than the actual kilogram value. As a result, some new functions were implemented (such as [llGetMassMKS](/functions/llGetMassMKS/)) which report the correct kilogram weight of an object.

Functionally speaking, lindograms can be used in the same way kilograms are used[^wiki-e13c2f], however only within the bounds of Second Life. Trying to export mass values from Second Life will often run into issues, caused by the use of lindograms as a base unit of measurement.

From a technical point-of-view, a lindogram is equivalent to a [*metric quintal*](https://en.wikipedia.org/wiki/Quintal), however it is not treated as such.

[^wiki-e13c2f]: With exception to some functions, such as [llSetPhysicsMaterial](/functions/llSetPhysicsMaterial/), which use kilograms, not lindograms. [llGetMassMKS](/functions/llGetMassMKS/) returns a kilogram value, not a lindogram value.

## See also

### Functions

- [llGetObjectMass](/functions/llGetObjectMass/) — Gets the object mass (in lindograms)
- [llGetForce](/functions/llGetForce/) — Gets the objects force
- [llGetOmega](/functions/llGetOmega/)
- [llGetVel](/functions/llGetVel/)
- [llGetTorque](/functions/llGetTorque/)
- [llGetAccel](/functions/llGetAccel/)
- [llGetMassMKS](/functions/llGetMassMKS/) — Get the mass of an object (in kilograms)

---

*Source: [LlGetMass](https://wiki.secondlife.com/wiki/LlGetMass) on the Second Life Wiki. Content from the Second Life Wiki article LlGetMass (revision 1214523, 2023-09-04), CC BY-SA 3.0.*

---

From lsl.dev: https://lsl.dev/functions/llGetMass/