Pending review

Design planning guide

Imperial and metric dimensions without conversion drift

Use one canonical measurement model while displaying feet, inches, meters, and centimeters clearly.

Created 2026-08-02Author: not yet recordedQualified reviewer: not yet suppliedSubstantive review date: pending

Direct answer

Store and calculate in one canonical unit, convert only at input and display boundaries, and round for presentation rather than repeatedly rounding the geometry. Always label the unit beside a number.

Planning workflow

Choose the unit system your measurements and collaborators actually use.
Enter full precision from the source measurement, including fractions where known.
Convert once into the project's canonical value and keep that value unchanged when toggling display units.
Display an alternate-unit equivalent for communication, not as a second editable truth.

Formula or decision logic

Exact conversions are 1 inch = 25.4 millimeters and 1 foot = 304.8 millimeters. Area conversion must square the factor: 1 square foot = 0.09290304 square meter. Volume conversion must cube it. Never convert area by applying a linear conversion factor.

Worked planning example

A wall entered as 11 ft 0 1/4 in is 132.25 inches. Multiplying by 25.4 gives 3,359.15 mm. A metric display can show 3.359 m while the stored value remains 3,359.15 mm. Switching back should reproduce 11 ft 0 1/4 in, not a rounded 11 ft.

Open this starting state in AtriBuild Use the related calculator Review Two-bedroom ranch concept

Limitations and review boundary

Display precision does not prove measurement accuracy.
Nominal product names can differ from actual dimensions.
Local drawings and permits may prescribe a required notation or unit system.

Conceptual planning onlyAtriBuild does not provide architectural or engineering services, stamped plans, permit approval, code-compliance verification, contractor bids, or construction guarantees. Verify dimensions, assemblies, utilities, quantities, prices, permits, and safety decisions with qualified local professionals.

Primary sources

Guide for the Use of the International System of Units (SI)National Institute of Standards and Technology; accessed 2026-08-02. Source scope may differ from this project.

Imperial and metric dimensions without conversion drift

Direct answer

Planning workflow

Formula or decision logic

Worked planning example

Limitations and review boundary

Primary sources

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