HoYoLAB is a website/app that contains communities and tools for all of miHoYo's games—including Genshin Impact. Among its growing number of tools is the Enhancement Progression Calculator, which is a handy upgrade farming guide for characters, weapons, Talents, and Artifacts.
To use the Enhancement Progression Calculator, you first need to log into HoYoLAB via its offical website or by downloading the app for free through the App Store or Google Play Store. Select the Tools section on the lefthand corner of the website or the bottom of the app to find the Enhancement Progression Calculator.
Inside the Calculator, you can choose between finding the upgrade requirements for characters, weapons, and Artifacts. The Talents section is on the same page as the characters section. The app also has a function to sync your existing character data, which opens up the Already Owned tab beside All.
All you need to do is choose a character, weapon, or Artifact and input the appropriate minimum and maximum level values, and the Calculator will generate the exact cost in materials, Mora, and Artifact EXP. However, character EXP is only represented through Hero's Wits—not Wanderer's Advice or Adventurer's Experience.
For example, in the image above, Kamisato Ayaka's level was set to 12 to 63, so the Calculator generated the materials required to get Ayaka from level 12 to 63. The same logic applies to the weapon and Artifact sections.
The only difference that applies to Artifacts is that you can input a maximum of five—one for each Artifact type.
Check out our guide on How to claim Genshin Impact Daily Check In Rewards to find out another feature you can find in HoYoLAB.