[Home](./index.md) > [bitburner](./bitburner.md) > [HacknetServersFormulas](./bitburner.hacknetserversformulas.md) > [levelUpgradeCost](./bitburner.hacknetserversformulas.levelupgradecost.md) ## HacknetServersFormulas.levelUpgradeCost() method Calculate cost of upgrading hacknet server level. **Signature:** ```typescript levelUpgradeCost(startingLevel: number, extraLevels?: number, costMult?: number): number; ``` ## Parameters

Parameter	Type	Description
startingLevel	number	starting level
extraLevels	number	_(Optional)_ amount of level to purchase (defaults to 1)
costMult	number	_(Optional)_ player cost reduction (default to 1)

**Returns:** number The calculated cost.