How are composite rates determined?

  1. Law
  2. CFR 31
  3. Money and Finance: Treasury
  4. Regulations Relating to Money and Finance
  5. Fiscal Service, Department of the Treasury
  6. Bureau of the Fiscal Service
  7. Offering of United States Savings Bonds, Series I
  8. General Information
  9. How are composite rates determined?

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§ 359.14 How are composite rates determined?

Composite rates are set according to the following formula (See appendix A to part 359 for examples of calculations involving composite interest rates.):

Composite rate = {(Fixed rate ÷ 2) + Semiannual inflation rate + [Semiannual inflation rate × (Fixed rate ÷ 2)]} × 2.[2]

Footnotes - 359.14

[2] Example for I bonds issued May 2002-October 2002:

Fixed rate = 2.00%

Inflation rate = 0.28%

Composite rate = [0.0200 ÷ 2 + 0.0028 + (0.0028 × 0.0200 ÷ 2)] × 2

Composite rate = [0.0100 + 0.0028 + 0.000028] × 2

Composite rate = 0.012828 × 2

Composite rate = 0.025656

Composite rate = 0.0257 (rounded)

Composite rate = 2.57% (rounded)


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