Calculate your I Bond composite rate, total return, and compare against a High-Yield Savings Account.
How I Bond rates work: The composite rate combines a fixed rate (set at purchase, never changes) and a semi-annual inflation adjustment based on CPI-U. Composite rate = fixed + 2×inflation + fixed×inflation. Rate resets every 6 months.
I Bond Details
Annual purchase limit: $10,000/person
Min 12 months; must hold 5+ years to avoid penalty