Clash of Clans Gem Calculator - Time and Resource Costs

Calculate how many gems you need to finish an upgrade early or to buy missing resources in Clash of Clans. Enter remaining time or the amount of Gold, Elixir or Dark Elixir you need.

Gem costs follow diminishing returns: longer timers and larger resource packs cost fewer gems per unit. This tool uses the standard in-game conversion formulas.

How Gem Costs Work in Clash of Clans

Gems can skip upgrade timers or buy resources instantly. Costs use diminishing returns: the more time or resources you buy at once, the fewer gems you pay per unit.

Time to Gems

Finishing an upgrade early costs gems based on the remaining time. Short timers are expensive per minute; long upgrades (many days) are cheaper per hour. Use the Time to Gems mode to see the cost before you spend.

Resources to Gems

You can buy Gold, Elixir or Dark Elixir with gems when you are short for an upgrade. Dark Elixir is much more expensive per unit than Gold or Elixir. Large purchases are more efficient than many small ones.

Tips

• Books and potions from the Trader are often better value than raw gems for long upgrades.
• Avoid gemming small resource gaps when possible - farm or wait instead.
• The 6th builder (OTTO / B.O.B.) is one of the best permanent gem investments in the game.

This Clash of Clans gem calculator provides estimates based on common in-game conversion patterns. Exact costs can vary slightly with game updates. Not affiliated with Supercell.