In global fixed-income and commodities markets, securities—such as US Treasury notes, Eurodollar futures contracts, and municipal bonds—are historically traded and quoted using fractional tick fractions rather than pure decimals. A financial news terminal or broker statement might list a Treasury bond price as 102.16, where .16 does not represent sixteen hundredths (0.16), but rather 16/32nds of a dollar (equivalent to 102.50 in standard decimal currency).
Performing mathematical calculations directly on these raw fractional quote strings causes severe financial calculation errors. To bridge the gap between historical fractional market conventions and modern arithmetic models, Google Sheets provides two specialized financial converter functions: DOLLARDE (Dollar Decimal) and DOLLARFR (Dollar Fraction). This guide explains how to convert fractional quotations to decimals and back with institutional precision.
Understanding Fractional Trading Price Conventions
In fixed-income terminology, fractional prices are represented as an integer part and a fractional part separated by a decimal point:
Quoted Number = Integer + (Fractional Part / Denominator)
Common financial market denominators include:
- 8: Grain commodities and legacy equity fractions (1/8th = 0.125).
- 16: Short-term debt paper (1/16th = 0.0625).
- 32: US Treasury notes and bonds (1/32nd = 0.03125).
Syntax and Parameter Breakdown
1. The DOLLARDE Function (Fraction to Decimal)
=DOLLARDE(fractional_dollar, fraction)
Converts a price expressed in fractional format into a true decimal number.
2. The DOLLARFR Function (Decimal to Fraction)
=DOLLARFR(decimal_dollar, fraction)
Converts a standard decimal price back into fractional trading notation.
Parameter Reference
- fractional_dollar / decimal_dollar: The price value to convert (e.g.
100.16or100.50). - fraction: The integer denominator defining the fraction’s base (e.g.
32for 32nds,16for 16ths). Must be an integer >= 1.
Step-by-Step Practical Implementation
Suppose you import a portfolio of Treasury bonds with prices quoted in 32nds:
Structure your Google Sheet rows:
A1: Bond Identifier | B1: Quoted Fraction | C1: Denominator | D1: Decimal Value | E1: Reconverted Fraction
A2: US T-Bond 2030 | B2: 102.16 | C2: 32 | D2: =DOLLARDE(B2, C2) | E2: =DOLLARFR(D2, C2)
A3: US T-Bond 2035 | B3: 98.08 | C3: 32 | D3: =DOLLARDE(B3, C3) | E3: =DOLLARFR(D3, C3)
A4: US T-Bond 2040 | B4: 105.24 | C4: 32 | D4: =DOLLARDE(B4, C4) | E4: =DOLLARFR(D4, C4)
Google Sheets calculates:
- Row 2:
102 + (16/32)= 102.50 - Row 3:
98 + (8/32)= 98.25 - Row 4:
105 + (24/32)= 105.75
Comparison: DOLLARDE vs Direct Mathematical Division
| Conversion Technique | Handles Non-Zero Integers | Maintains Dynamic Parameter Denominators | Prevents Floating-Point Rounding Drift |
|---|---|---|---|
| DOLLARDE Function | Automatic (Splits integer and mantissa natively) | Yes (Single cell parameter) | Yes (Financial standard rounding) |
| Manual Formula (INT + MOD) | Requires complex helper columns | Prone to formula syntax typos | Susceptible to IEEE 754 precision issues |