[Home](./index.md) > [bitburner](./bitburner.md) > [HacknetServersFormulas](./bitburner.hacknetserversformulas.md) > [cacheUpgradeCost](./bitburner.hacknetserversformulas.cacheupgradecost.md) ## HacknetServersFormulas.cacheUpgradeCost() method Calculate cost of upgrading hacknet server cache. **Signature:** ```typescript cacheUpgradeCost(startingCache: number, extraCache?: number): number; ``` ## Parameters

Parameter	Type	Description
startingCache	number	starting cache level
extraCache	number	_(Optional)_ amount of levels of cache to purchase (defaults to 1)

**Returns:** number The calculated cost.