[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 | amount of level to purchase (defaults to 1) | | costMult | number | player cost reduction (default to 1) | Returns: number The calculated cost.