If you play Forge of Empires seriously, you've hit this problem: is this GB investment actually worth it. That's exactly what GB Investment Calculator calculates.
Every FP you put into a Great Building is an investment. This tool calculates the exact return: base rewards, Arc bonus multiplier, position-specific payouts, and break-even math. Compatible with all GBs from Alcatraz through Deal Castle.
Try the GB Investment Calculator Now
The full interactive tool is available on the main calculator page.
Open FoE Calculator →How the GB Investment Calculator Works
The calculation model uses the standard FoE game math: base GB rewards scale with level according to the published curves, Arc bonuses multiply rewards by (1 + Arc%/100), and position-specific payouts follow the tiered P1-P5 distribution. Every number the calculator returns matches what you'd calculate manually — it just does it in milliseconds.
Common Questions
Is the GB Investment Calculator accurate?
Yes — the underlying formulas are based on the game's published mechanics. If you notice any discrepancy with in-game values, please report it via the contact page.
Does the tool account for the Arc bonus?
Every calculation applies your specified Arc bonus. If you're unsure of your exact Arc bonus, check your Arc GB level and use the corresponding percentage from the standard Arc reward table.
Do I need an account?
No. The tool works entirely in your browser with no login, no signup, no data collection beyond anonymous analytics.
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Use the GB Investment Calculator
Use the free calculator to test your build against the exact game math.
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