# Function: molecularMass()

[**lifecycle-kit**](https://jonbogaty.com/lifecycle-kit/api/readme/index.md)

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[lifecycle-kit](https://jonbogaty.com/lifecycle-kit/api/readme/index.md) / [chem](https://jonbogaty.com/lifecycle-kit/api/chem/readme/index.md) / molecularMass


# Function: molecularMass() {#function-molecularmass}


> **molecularMass**(`counts`): `number`

Defined in: [chem/elements.ts:225](https://github.com/jbcom/lifecycle-kit/blob/074e4e7b8038d3e2de9eb44c4b5b5aee0ef02b48/src/chem/elements.ts#L225)

Mass of a formula given as element counts, in u.


## Parameters {#parameters}



### counts {#counts}


`Record`\<`string`, `number`\>


## Returns {#returns}


`number`