Bridging the digital-to-tape gap
CAD drawings, spreadsheets and product specs speak decimal inches (3.4375); your tape measure speaks fractions (3 7/16). The calculator finds the nearest fraction down to 1/32 of an inch and shows how far off it is — most of the time the nearest 1/16 is the practical answer and the 32nd is the machinist's.
Sources and standards
Where these figures come from
Every formula on this page is implemented from the published reference material below. Where a value depends on a regional code, the calculator lets you override it rather than assuming one jurisdiction.
- NIST Office of Weights and Measures — the US customary and SI conversion factors used throughout this tool.
- International Code Council — the International Residential Code and International Building Code.
Figures, formulas and reference tables last verified: 19 September 2026.